Vanilla-Mango Tartelettes

Yes, it's officially fall. Time to dust off the coats, scarves, gloves and snow shovels - they will become handy really soon! 
Since I am still in denial about that fall arriving (join me, denial it's fun!), I am going to behave as if it is still 80 degrees and sunny outside, and prepare a dessert with the oh-so-tropical-and-summer-y mango! 

Catching a tan in the sun! I mean, in the oven...

And now we're cooling off in room temperature!

The tartelettes crust in this recipe is based on a chocolate "porcupine" recipe by Micky Shemo.
The vanilla filling is based on an "Egg Tarts" recipe by Gal. 

Vanilla-Mango Tartelettes
Yields: 12 Tartelettes

WHAT:
for the crust: 

• 50 grams sugar
• 1 stick unsalted butter, cold, cubed
• 1 egg
• 210 grams (1 1/2 cups) all-purpose flour
• 1/2 tsp baking powder
• [optional, if mixture is too dry] 1-2 tsp milk
• [optional, if mixture is too soft/wet] 1-2 tsp flour

for the vanilla filling: 

• 300 grams (3/4 can) sweetened condensed milk.
  [Keep the 1/4 leftover can in the fridge, well wrapped (it should be good for a week or two) and prepare Caramel Apple Blondies next week!]
• 4 eggs
• 200 ml milk
• 1 tsp vanilla extract / paste

for the mango frosting:

• 100 grams peeled, cubed mango (fresh or frozen, not thawed)
• 250 ml (1 cup) heavy whipping cream, cold
• 3 heaping tbsp sugar
• 1 heaping tbsp vanilla pudding mix (powder)

HOW:

• Crust: Sift flour and baking powder into a large bowl.
• In a food processor or a mixer with a flat beater, mix together butter and sugar until well combined. 
• Add in egg and a quarter of the flour mixture. Mix for a few seconds. 
• Add in the rest of the flour mixture. Mix until a large dough-ball is formed, not beyond. 
• If mixture is too dry and not solidifying into a ball, add 1 or 2 tsp of milk, as needed. 
• If mixture is too soft/wet and not solidifying into a ball, add 1 or 2 tsp of flour, as needed. 
• Form the dough into a 1/2 inch thick disc shape. 
• Wrap the dough in plastic wrap, and refrigerate for 30 minutes (or more). 
• Pre-heat oven to 390 degrees (F)
• Remove refrigerated dough from plastic wrap, and knead/mold a little with your hands, to warm it up a bit. 
• Using a rolling pin, flatten the dough to be ~3-4 mm thick on a generously-flour-dusted surface. 
• Using a 4-inch-diameter cookie/biscuit cutter or a similar tool with which you can cut round shapes (e.g. a small bowl), cut 12 "discs" out of the flattened dough. 
• [Leftover dough? Make some jam sandwich cookies!]
• Line a regular cupcake/muffin pan with the dough "discs" (no need to oil the pan or line it with paper liners), pressing each disc to the bottom and sides of each cupcake/muffin "cavity" to form the tartelettes' crusts. 
• Using a fork, puncture the bottom of each disc a couple of times (to prevent air-pockets). 
• Wrap the pan tightly in plastic wrap or aluminum foil and freeze until pre-bake assembly. 
• Filling (prepare while pan is in the freezer): 
• In a medium bowl, whisk together sweetened condensed milk, eggs and vanilla extract/paste until well combined. 
• Strain the mixture through a fine mesh into a clean medium-large bowl. 
• Add milk to the mixture and whisk everything together until well combined. 
• Transfer mixture to a vessel with a pouring tip/nozzle (such a large measuring glass). 
• Pre-bake assembly: Take out the pan with the tartelette-crusts from the freezer, remove wrap.
• Carefully fill each tartelette crust with the filling-mixture until completely full. 
• Carefully transfer the pan to the oven. Bake tartelettes for 10 minutes. 
• Reduce oven heat to 355 degrees (F) and bake for another 10 minutes. 
• Turn off the oven, leave the tartelettes in the oven for another 10 minutes. 
• Remove pan from the oven, let it sit in room temperature until completely cooled down, at least 1-2 hours. 
• [The tartelettes will puff-up in the oven, then lose some of their volume while cooling down, especially in the center (see the "in the oven" image vs. the "cooling-off" image above) - it's fine.]
• At this stage, it is recommended to take the tartelettes out of the pan (it would be harder to do so once they are frosted).
  You can put each tartelette in a cupcake-paper-liner at this stage, if you'd like.
  In order to take the tartelettes out of the pan, use a very thin small knife or a small offset spatula (slide knife/spatula between the crust and the pan and run it all around each cavity in the pan until tartelette edges are completely released from the sides of the cavity. Now slide the knife/spatula underneath the tartelette to release it from the bottom of the cavity and use it to gently lift the tartelette on one side; take the tartelette out of the pan with your other hand). 
• Mango frosting: Puree the mango in a food processor or blender with 1/2 cup heavy cream until a smooth paste is formed. 
• Transfer the mango paste to a mixer with a whipping attachment, and whip with the other 1/2 cup heavy cream and vanilla pudding mix until well combined and firm. 
• If the frosting is not firming up well and you are concerned about over-whipping which may "break" the heavy cream, simply mix as much as you can until almost completely firm, wrap the frosting and put it in the fridge for a few minutes - that should further firm up the mixture a bit. 
• Using a pastry bag with a star tip, frost each tartelette with the frosting. 
• Enjoy!

Leftovers? Keep the tartelettes in an air-tight container in the fridge. 

The tartelettes are at their best on the first two days, afterwards the crust may become softer. I recommend to consume within 4-5 days.

Caramel-Apple Blondies

I came across a lot of apple-related recipes recently - not surprising, given that last week was the Jewish New Year holiday. 
I admit - I am not a big fan of recipes with apples in them, but some of these recipes looked really good!. Plus, Halloween is just around the corner (maybe a couple of corners...), so caramel apples seemed like a classic choice to base my next dessert on. 
Long story short - I pulled myself together, temporarily ignored the fact that I am not an apple-dessert fan and that I need to deal with caramel for this one, and what do you know - eventually these turned out great!

These blondies did not just turn out great by a coincidence; after all, they are based on awesome recipes: 

The blondies recipe is taken from a "white chocolate and raspberry blondies" recipe (without the raspberries, obviously...) by Natalie Levin and Efrat Lichtenstadt, which also appears in their amazing baking book, The Sweet Book.

The apple layer and the hazelnut streusel recipes are taken from a "hazelnut crumble apple pie" recipe by Natalie Levin. 

The caramel/taffy recipe (which, BTW, is a great easy alternative to the classic "make caramel, add in cream and make a complete mess in your kitchen" butterscotch/taffy recipe) is taken from a "Twix (chocolate and salted taffy) Tart" recipe from the very same Sweet Book. 

Caramel-Apple Blondies
Yields: 16 Blondies

WHAT:
for the blondies:

• 1 stick unsalted butter, melted
• 190 grams sugar
• 2 eggs
• 1 tsp vanilla extract/paste
• a pinch of salt
• 140 grams (1 cup) all purpose flour
• 90 grams (3 ounces) white chocolate, chopped. 

for the apples layer:

• 2 granny-smith apples, peeled and chopped to small cubes
• a squeeze of lemon/lime juice
• grated peel out of 1/2 a lemon/lime. 
• 20 grams (2 tbsp) sugar
• a pinch of cinnamon powder
• 1/2 tsp vanilla extract/paste
• 1 tbsp unsalted butter

for the hazelnut streusel: 

• 30 grams (1 ounce) blanched hazelnuts
• 90 grams (3 ounces) all purpose flour
• 5/8 stick unsalted butter, cold, cubed
• 50 grams sugar

for the caramel/taffy frosting:

• 100 grams (1/4 can) sweetened condensed milk
  [Keep the 3/4 leftover can in the fridge, well wrapped (it should be good for a week or two) and prepare Vanilla-Mango Tartelettes next week!]
• 20 grams sugar
• 1 tbsp unsalted butter
• 5 grams (1/2 tbsp) glucose or corn syrup
• 250 ml (1 cup) heavy cream, cold
• 1 heaping tsp vanilla pudding mix (powder)
• cinnamon powder for decoration

HOW:

• Preheat oven to 350 degrees (F). 
• Apples layer: Place sugar in a small/medium pot/pan; put pot/pan over a medium heat, until sugar is melted. 
• Add in the rest of the apples-layer ingredients. 
• Cook over a medium heat until apples begin to soften, stir occasionally (apples will fully soften during the final baking stage)
• Remove from heat, strain apples from excess liquids and set aside to completely cool in room temperature.
• Hazelnut streusel: Place hazelnuts and flour in food processor, and process until hazelnuts are well ground. 
• Add in butter and sugar; continue processing until crumbs are formed. 
• Wrap well and keep refrigerated until pre-bake assembly stage. 
• Blondies: In a large bowl, mix together butter and sugar. 
• Add in eggs, vanilla and salt, mix together until well combined. 
• Sift in the flower, add in the chopped white chocolate, mix together until combined, not beyond. 
• Pre-bake assembly: (optional) Line an 8x8" or 9x9" square pan with parchment paper. 
• Transfer the blondies batter to the pan; evenly spread and smooth the batter in the pan using an angled spatula or a spoon. 
• Top the blondies batter with the apples (try to spread them evenly). 
• Top the apples with the streusel (try to spread it evenly) - apples should be completely covered with streusel.
• Transfer pan to the oven and bake for 35-40 minutes, until streusel is lightly golden. 
• Let pan completely cool in room temperature, at least 1 hour. 
• Using a large sharp knife, carefully cut the cake to 16 2x2" (if pan is 8x8") or 2 1/4 x 2 1/4" (if pan is 9x9") squares. 
• Caramel/taffy frosting (start preparing while blondies are in the oven): Place condensed milk, sugar, butter and glucose/corn-syrup in a small pan, cook over medium-high heat, stirring occasionally, until mixture thickens and slightly darkens. 
• Set aside to cool down in room temperature. 
• After both caramel/taffy and blondies have cooled down: In a mixer with a whipping attachment, whip together the caramel/taffy, 1/2 cup of heavy cream and the vanilla pudding mix until well combined. 
• Add in the other 1/2 cup of heavy cream, and continue whipping until well combined and firm. 
• [note: be careful not to over-whip the frosting, which may "break" the heavy cream and turn the mixture into a liquid mess; the frosting may be a bit grainy due to caramel bits that haven't fully "dissolved"; this may make the frosting look less appealing, but trust me - it will not affect the taste :) the important thing is that the frosting will be firm]
• Using a pastry bag with a star tip, top each blondie with a "star" of frosting. 
• Sprinkle a little bit of cinnamon on top of the blondies. 
• Enjoy!

Leftovers? Keep the blondies refrigerated in an air-tight container up to 4-5 days. The blondies are at their best when at room temperature, so leave refrigerated blondies out in room temperature for 15-30 minutes before digging into them. 

"Strawberry Banana Shake" Tartelettes

I don't want to get into too much detail about how last weekend has gone off to a bad start for me, I'll just mention that not having cable tv and internet service for 24 hours for a screen-addict like me can be a tad frustrating... Once connection was restored though - my weekend has miraculously improved! It was even further improved while (and after) making these awesome tartelettes, inspired by the loved-by-all (most?) strawberry banana shake.

I came across a recipe for a banana-cheesecake not too long ago (full reference to follow) and I really wanted to use it (as a tartelette filling, of course - what else?), but I wanted to pair it with a great frosting that will complement the banana flavor, and I thought "well, the strawberry-banana combination is already out there - it's good, it's popular, so I won't have too much explaining to do - let's tartelette-it-up with some strawberry frosting!".

The tartelettes crust in this recipe is based on a chocolate "porcupine" recipe by Micky Shemo.
The banana-cheese filling is based on a banana-cheesecake-with-caramel recipe by the cookie fairy - I recommend browsing through her blog, even just for the photos - they are breathtaking!

"Strawberry-Banana-Shake" Tartelettes
Yields: 12 Tartelettes

WHAT:
for the crust: 

• 50 grams sugar
• 1 stick unsalted butter, cold, cubed
• 1 egg
• 210 grams (1 1/2 cups) all-purpose flour
• 1/2 tsp baking powder
• [optional, if mixture is too dry] 1-2 tsp milk
• [optional, if mixture is too soft/wet] 1-2 tsp flour

for the banana-cheese filling (all ingredients should be in room temperature): 

• 2 ripe bananas
• a squeeze of lime juice or lemon juice
• 110 grams sugar, divided to 20 grams and 90 grams
• 227 ml /  8 oz cream cheese (1 package)
• 113 ml / 4 oz sour-cream (1/2 small package)
• 2 eggs
• 1 tsp vanilla extract / paste

for the strawberry frosting (all ingredients except powdered sugar and pudding mix should be cold from the fridge):

• 8 - 10 large strawberries
• 1 cup heavy cream
• 113 ml / 4 oz sour-cream (1/2 small package)
• 3 overloaded tbsp powdered sugar
• 1 overloaded tbsp vanilla pudding mix (powder)

for the white-chocolate-coated strawberry decoration [optional]

• 6 beautiful strawberries
• ~60-70 grams white chocolate

HOW:

• Crust: Sift flour and baking powder into a large bowl.
• In a food processor or a mixer with a flat beater, mix together butter and sugar until well combined. 
• Add in egg and a quarter of the flour mixture. Mix for a few seconds. 
• Add in the rest of the flour mixture. Mix until a large dough-ball is formed, not beyond. 
• If mixture is too dry and not solidifying into a ball, add 1 or 2 tsp of milk, as needed. 
• If mixture is too soft/wet and not solidifying into a ball, add 1 or 2 tsp of flour, as needed. 
• Form the dough into a 1/2 inch thick disc shape. 
• Wrap the dough in plastic wrap, and refrigerate for 30 minutes (or more). 
• Remove refrigerated dough from plastic wrap, and knead/mold a little with your hands, to warm it up a bit. 
• Using a rolling pin, flatten the dough to be ~3-4 mm thick on a generously-flour-dusted surface. 
• Using a 4-inch-diameter cookie/biscuit cutter or a similar tool with which you can cut round shapes (e.g. a small bowl), cut 12 "discs" out of the flattened dough. 
• [Leftover dough? Make some jam sandwich cookies!]
• Line a regular cupcake/muffin pan with the dough "discs" (no need to oil the pan or line it with paper liners), pressing each disc to the bottom and sides of each cupcake/muffin "cavity" to form the tartelettes' crusts. 
• Using a fork, puncture the bottom of each disc a couple of times (to prevent air-pockets). 
• Wrap the pan tightly in plastic wrap or aluminum foil and freeze until pre-bake assembly. 
• Filling (prepare while pan is in the freezer): Pre-heat oven to 355 degrees (F). 
• In a food processor or simply using a fork, Mash the bananas well. Put the banana puree in a small pot. 
• Add lemon/lime juice and 20 grams of sugar into the pot. Cook on low heat for a few minutes, until sugar dissolves. 
• Remove pot from heat, transfer the banana puree to a small bowl, set aside in room temperature for cooling. 
• In a mixer with a whipping balloon or a flat beater, mix together the cream-cheese and 90 grams sugar until combined. 
• Add in sour-cream, eggs (one at the time; add the second egg only after the first one was well combined into the mixture), banana puree and vanilla extract / paste, until well combined. 
• Transfer the mixture into a vessel with a pouring tip such as a large measuring glass. 
• [Optional] Decoration: Half the strawberries lengthwise.
• Melt the white chocolate in the microwave or over a double boiler. Stir until smooth. 
• Hold each strawberry-half on its wider side and dip in the melted white chocolate to coat it almost all the way up. Place the coated strawberry-halves on a surface lined with parchment paper, flat-side down. 
• Set aside either in room temperature or in the fridge (well wrapped) until after the frosting stage. 
• Pre-bake assembly: Take out the pan with the tartelette-crusts from the freezer, remove wrap.
• Fill each tartelette crust with the banana-cheese filling until completely full. 
• Carefully transfer the pan to the oven. Bake tartelettes for 25-30 minutes. 
• Remove pan from the oven, let it sit in room temperature until completely cooled down, ~1 hour. 
• At this stage, it is recommended to transfer the tartelettes to the container that will be put in the fridge for the final cooling/setting.
  You can put each tartelette in a cupcake-paper-liner at this stage, if you'd like.
  In order to take the tartelettes out of the pan, use a very thin small knife or a small offset spatula (slide knife/spatula between the crust and the pan and gently lift the tartelette on one side; take the tartelette out of the pan with your other hand). 
• Strawberry frosting: Puree the strawberries in a food processor until smooth. 
• Strain strawberry puree through a fine-mesh strainer for an extra-smooth puree. 
• Whip together the strained strawberry puree with all of the other frosting ingredients on high speed, until firm. 
• If the frosting is not firming up well and you are concerned about over-whipping which may "break" the heavy cream, simply mix as much as you can until almost completely firm, wrap the frosting and put it in the fridge for a few minutes - that should further firm up the mixture a bit. 
• Using a pastry bag with a star tip, frost each tartelette with the frosting. 
• If you have prepared the optional decoration: Top each tartelette with a chocolate-coated-strawberry-half, flat-side down. 
• Refrigerate the tartelettes in an air-tight container for at least 4 hours, preferably overnight.
• Enjoy!

Leftovers? Keep the tartelettes in an air-tight container in the fridge. 

The tartelettes are at their best on the first two days (after the overnight cooling), afterwards the crust may become softer and the strawberry may lose its freshness and become somewhat "tired". 

I recommend to consume within 4-5 days.

Quicky - Jam Sandwich Cookies

Remember my Peanut Butter Chocolate Sandwich Cookies? Of course you do - it was published only a week ago... 
Well, these cookies are very similar - I'm regularly using the dough in this recipe to make a classic pie-crust.
These jam sandwich cookies are a simple way of using the pie-crust-dough's leftovers.
And just like their chocolaty cousins - feel free to use all of the dough only for making these cookies - no need to bake a pie just so you'll have dough leftovers for making cookies :)

The cookie-dough recipe is based on a chocolate "porcupine" recipe by Micky Shemo.

You can use any jam that you like - strawberry/raspberry/apricot/... - as long as it's smooth  - don't go for the preserves that have fruit chunks in them. 

Jam Sandwich Cookies
Yields: 30-35 2-inch-diameter cookie-sandwiches

WHAT:
for the cookies:

• 50 grams sugar
• 113 grams (1 stick) unsalted butter, cold, cubed
• 1 egg
• 210 grams all-purpose flour
• 1/2 tsp baking powder

for the filling:

• 2 overloaded tbsp jam

HOW:

• Cookies: Preheat oven to 355 degrees (F). 
• Sift flour and baking powder into a large bowl.
• In a food processor or a mixer with a flat beater, mix together butter and sugar until well combined. 
• Add in egg and a quarter of the flour mixture. Mix for a few seconds. 
• Add in the rest of the flour mixture. Mix until a large dough-ball is formed, not beyond. 
• Form the dough into a 1/2 inch thick disc shape. 
• Wrap the dough in plastic wrap, and refrigerate for 30 minutes (or more). 
• Remove dough from plastic wrap, and knead/mold a little with your hands, to warm it up a bit. 
• Using a rolling pin, flatten the dough to be about 3-4 mm thick on a generously-flour-dusted surface. 
• Using a cookie-cutter in any shape/size you like, cut cookies out of the dough.
• [Optional] Using a round pastry-bag tip or a small round cutting tool, remove the center of half of the cookies. 
• Filling: Warm the jam in the microwave (10-15 seconds) or over a double boiler. Stir until smooth. 
• Assembly: Place a small "blob" of jam in the center of each cookie that does not have a hole in it / half of the cookies.
• Create cookie sandwiches by placing a cookie with a hole in it / "clean" cookie over each "blob"ed cookie. Gently press the edges of each cookie-sandwich to better stick the cookies together. 
• Place all cookies (in a single layer) on a cookie sheet lined with parchment paper.
• Bake cookies for 10-12 minutes. 
• Remove cookie sheet from the oven, and let it sit in room temperature to allow cookies to *completely* cool down (jam in the cookies will be *hot*!). 
• Enjoy!

Leftovers? Keep the cookies in room temperature in an air-tight container / cookie jar. 

Black & White Tartelettes

My husband and I were on a double mission:

1. For my husband: Find a youth-size Red Sox baseball cap. 
2. For me: Find hazelnuts for the dessert I had in mind. 

Surprisingly, we were able to find both on Newbury street! I was so ready to give up on the hazelnuts - after checking out a bunch of stores, I was almost convinced that walnuts, pecans and cashews are the only types of nuts in the world. But this mini-market (or, micro-market) on Newbury street eventually came to the rescue - it even had peeled and unpeeled hazelnuts to choose from! I took the peeled ones, of course... peeling is a pain!...

This dessert is basically my attempt to re-create the flavor combination that the amazing Black & White dessert from Babbo Pizzeria has - Chocolate, Crème fraîche, Hazelnuts and Caramel. 
Well - I decided that Greek yogurt is close enough to Crème fraîche, and that dulce de leche is close enough to Caramel (it isn't, really... but after a couple of Caramel-related disasters that I had in the kitchen, I stuck to the safer choice; plus, I already had a jar of dulce de leche that was just begging me to use it... how could I refuse?...). 

Note that I am not using special tartelette pans (I don't have any... yet...) - instead, I'm using a regular cupcakes/muffin pan. 

The tartelettes crust in this recipe is based on a chocolate "porcupine" recipe by Micky Shemo.
The inspiration for the nutty-bottom-layer is from a Pistachio-Chocolate Tart recipe by Chen Shukrun.
The chocolate layer is based on a Grappa-chocolate Tart recipe published on ynet.
The yogurt layer is based on a Cheese-Chocolate Spiral-Cake recipe by Carine Goren.

Black & White Tartelettes
Yields: 12 Tartelettes

WHAT:
for the crust: 

• 70 grams sugar
• 1 stick unsalted butter, cold, cubed
• 1 egg
• 210 grams (1 1/2 cups) all-purpose flour
• 10 grams (1 tbsp) unsweetened cocoa powder
• 1/2 tsp baking powder
• [optional, if mixture is too dry] 1-2 tsp milk
• [optional, if mixture is too soft/wet] 1-2 tsp flour

for the nutty-bottom-layer:

• 100 grams peeled hazelnuts
• a pinch of salt
• 35 grams sugar
• 2 tbsp vegetable oil (not olive oil!)

for the milk chocolate layer:

• 170 grams (6 ounce) milk chocolate
• 1/2 stick unsalted butter
• 1 egg
• 15 grams corn starch
• 20 grams all purpose flour
• a pinch of salt

for the yogurt layer:

• 70 grams white chocolate
• 30 ml heavy cream
• 200 grams (1 small package) Greek Strained Yogurt
• 25 grams sugar
• 1 egg
• 1 tsp corn starch

for the dulce de leche frosting:

• 2 overloaded tbsp dulce de leche
• 1 cup heavy cream
• 1 tsp vanilla pudding mix (powder)

for decoration (optional):

• peeled hazelnuts, coarsely-chopped. 

HOW:

• Crust: Sift flour, cocoa powder and baking powder into a large bowl.
• In a food processor or a mixer with a flat beater, mix together butter and sugar until well combined. 
• Add in egg and a quarter of the flour/cocoa mixture. Mix for a few seconds. 
• Add in the rest of the flour/cocoa mixture. Mix until a large dough-ball is formed, not beyond. 
• If mixture is too dry and not solidifying into a ball, add 1 or 2 tsp of milk, as needed. 
• If mixture is too soft/wet and not solidifying into a ball, add 1 or 2 tsp of flour, as needed. 
• Form the dough into a 1/2 inch thick disc shape. 
• Wrap the dough in plastic wrap, and refrigerate for 30 minutes (or more). 
• Pre-heat oven to 355 degrees (F). 
• Remove refrigerated dough from plastic wrap, and knead/mold a little with your hands, to warm it up a bit. 
• Using a rolling pin, flatten the dough to be ~3-4 mm thick on a generously-flour-dusted surface. 
• Using a 4-inch-diameter cookie/biscuit cutter or a similar tool with which you can cut round shapes (e.g. a small bowl), cut 12 "discs" out of the flattened dough. 
• [Leftover dough? Make some peanut-butter chocolate sandwich cookies!]
• Line a regular cupcake/muffin pan with the dough "discs" (no need to oil the pan or line it with paper liners), pressing each disc to the bottom and sides of each cupcake/muffin "cavity" to form the tartelettes' crusts. 
• Using a fork, puncture the bottom of each disc a couple of times (to prevent air-pockets). 
• Nutty bottom layer: In a food processor, finely grind the hazelnuts with salt and sugar. 
• Add in oil, and continue processing until well combined and mixture consistency resembles damp sand. 
• Put ~1 overloaded teaspoon of ground-nuts-mixture into each tartelette crust. 
• Using a small glass or another tool (or even a teaspoon), press the nuts-mixture firmly onto the crust bottom. 
• Wrap the pan tightly in plastic wrap or aluminum foil and freeze for ~10 minutes. 
• Remove pan from freezer, remove wrap. 
• Immediately transfer pan to the oven, bake for ~7 minutes.
• Take pan out of the oven, set aside in room temperature to cool down, until pre-bake assembly. Keep crusts in the pan. Crusts' bottoms might have risen a bit while being in the oven - they will "fall" back down while cooling. 
• Lower oven temperature to 300 degrees (F).
• Milk chocolate layer (prepare while pan is cooling down): Place milk chocolate and butter in a medium bowl. Heat in microwave or over a double boiler until chocolate and butter are melted. Mix together until well combined. Set aside to cool down a bit. 
• Beat egg (with a fork or a small whisk) in a small bowl for ~1 minute.
• Add egg into the cooled-down chocolate. Beat until egg is well combined - mixture should become very smooth and glossy. 
• Sift flour, corn starch and salt into the chocolate mixture. Beat together until well combined. 
• Yogurt layer: Place white chocolate and heavy cream in a small bowl. Heat in microwave or over a double boiler until chocolate is melted. Mix together until well combined. Set aside to cool down a bit. 
• In a medium bowl, mix together the Greek yogurt and the sugar until the sugar dissolves.
• Add in the egg and mix until well combined. 
• Add the white chocolate ganache to the yogurt mixture. Mix together until well combined. 
• Transfer a small amount (~1/3 cup) of the yogurt mixture to a clean small bowl. Add the corn starch to that bowl. Mix together until well combined. 
• Transfer the corn-starch-mixture back to the medium ball with the rest of the yogurt-mixture. Mix everything together until well combined. 
• Pre-bake assembly: After crusts have cooled down from their initial baking, fill each crust with the milk-chocolate mixture until ~1/2 full (I used a pasty bag with a large round metal tip). 
• Fill each tartelette crust with the yogurt mixture (on top of the milk-chocolate layer) until tartelette is completely full (the yogurt mixture is a bit more liquid-y, so using any vessel with a pouring tip such as a measuring glass should do the work). 
• Carefully transfer the pan to the oven. Bake tartelettes for 20-25 minutes. 
• Remove pan from the oven, let it sit in room temperature until completely cooled down, ~1 hour. 
• At this stage, it is recommended to transfer the tartelettes to the container that will be put in the fridge for the final cooling/setting.
  You can put each tartelette in a cupcake-paper-liner at this stage, if you'd like.
  In order to take the tartelettes out of the pan, use a very thin small knife or a small offset spatula (slide knife/spatula between the crust and the pan and gently lift the tartelette on one side; take the tartelette out of the pan with your other hand). 
• Dulce de leche frosting: Whip together all frosting ingredients on high speed, until firm. 
• Using a pastry bag with a star tip, frost each tartelette with the frosting. 
• [Optional] Decorate each tartelette with some coarsely chopped hazelnuts. 
• Refrigerate the tartelettes in an air-tight container for at least 4 hours, preferably overnight.
• Enjoy!

Leftovers? Keep the tartelettes in an air-tight container in the fridge. 

The tartelettes are at their best on the first two days (after the overnight cooling), afterwards the crust may become softer. 

I recommend to consume within 4-5 days.