A Birthday No Bake Caramel and Chocolate Biscuit Cake

No Bake Caramel and Chocolate Biscuit Cake (recipe by Gabriela Iancu, David Lebovitz, Pierre Herme)

Ingredients for cake base (recipe/idea/styling Gabriela Iancu) :
250g ground plain biscuits
50g melted unsalted butter

For the chocolate pastry cream (recipe Pierre Herme):
500g whole milk
4 large egg yolks
75g sugar
3 tablespoons cornstarch, sifted
200g bittersweet chocolate (I used Bonnat Madagascar and Ecuador 75% cocoa butter chocolate)
40g unsalted butter, at room temperature

Ingredients for caramel (recipe David Levotiz) :
200g sugar
90g unsalted butter
120g heavy cream
1 teaspoon sea salt

Make the cake base:
1. Add the biscuits broken in small pieces and the butter in a blender or food processor. Pulse few times until you will obtain a crumbly consistency. Be careful not to overmix, otherwise you will need to add more butter to bind the biscuits.

Make the caramel :
1. Add sugar in a heavy-bottomed, large saucepan. Melt the sugar over medium heat. Be careful not to burn it. Once burnt you will not be able to use it.
2. Once the sugar has melt (it should have a brown color), turn off the heat, add in the butter. Be careful, this will produce foam. Add the butter over the sugar just when it’s completely melt.
3. Pour in the heavy cream and stir until you will obtain a creamy sauce. Add the salt, mix and then let it cool.

Make the chocolate pastry cream :
1. In a small saucepan, bring the milk to a boil. Prepare an ice bath.
2. In the meantime, combine the yolks, sugar and cornstarch in a medium bowl and whisk together. Once the milk has reached a boil, temper the yolks by whisking a couple spoonfuls of the hot milk into the yolk mixture. Continue whisking and slowly pour the rest of the milk into the tempered yolk mixture.
3. Strain the mixture back into the saucepan to remove any egg that may have scrambled. Place the pan over medium heat and whisk vigorously and continuously until the mixture returns to a boil. Keep whisking vigorously for 1 to 2 more minutes (still over medium heat). Stir in the melted chocolate and then remove the pan from the heat.
4. Scrape the pastry cream into a small bowl and set it in the ice-water bath to stop the cooking process. Make sure to continue stirring the mixture at this point so it remains smooth.
5. Once the cream has cooled slightly from the ice-water bath and stir in the butter in three or four instalments. Return the cream to the ice-water bath to continue cooling, stirring occasionally, until it has completely cooled. The cream is now ready to use or store in the fridge.

Assembling the cake:
1. Using a cake pan (22cm, preferable with removable bottom), add one layer of crumbly biscuits at the bottom of the pan. Make sure to press it well and spread it on a even layer.
2. Continue by spreading one layer of chocolate cream, biscuits, caramel and so on.
4. Finish the cake by a final layer of biscuits, chocolate and caramel. Sprinkle bake hazelnuts over top. Keep it refrigerated, in the pan, at least 8 hours before cutting it, or better, over night.