Directions

• For the pastry cream – Whisk the egg yolks with sugar in the stand mixer until creamy; add cornstarch and flour that you combined well with the 2-3 tablespoons of that total milk needed. Add the vanilla extract. In the medium saucepan heat the milk until just before the boiling. Slowly pour in the mixture of egg yolks and cornstarch, continuously and vigorously whisking. It will start to thicken and after about 1 minute you will see it boiling. Take off the heat and cover with plastic wrap pressing it directly against the surface of the pastry cream, to prevent the formation of the skin. Once it is cooled, add the butter and mix well together.
• For the Praline – Roast the almonds and hazelnuts flat in a pan until they change the color, about 10 minutes at 400 °. Place them in a kitchen towel and try to rub them close together within the towel as much as possible – this will get the skin off. Place the sugar in a saucepan on medium heat and wait until it starts melting and changing the color. Occasionally gently shake the saucepan to create some movement in the sugar. Once it is melted completely, it will take about 7-10 min, turn off the heat and add the almonds and hazelnuts. Mix until the nuts are fully coated in the caramel. Leave to cool off. Once the mixture is cooled off, break it in smaller pieces using a kitchen hammer or another heavy object – put them in a food processor and grind for about 3-5 minutes. Do not add anything, the nuts will release their oils and sugar will melt a bit, and you will get a wonderful praline paste. Add the paste to the pastry cream and mix well until fully incorporated.
  
  
• For the biscuit – Roast the hazelnuts and get the skin off once cooled, or buy roasted and unsalted hazelnuts instead. Grind the hazelnuts and combine with cocoa. Beat the egg whites with the sugar until the shiny peaks form. Using spatula, gently fold the egg whites mixture to the hazelnut and cocoa mixture making sure not to overdo the mixing which deflates the whites. Spread the mixture in a large baking pan lined with parchment paper. Use the largest baking pan you have – you want to be able to divide it to at least six strips. Bake for about 30 min at 350°. Let it cool and then with kitchen scissors, cut the biscuit together with the parchment paper into strips. Gently peel the parchment paper of the strips and start assembling the cake.
  
• Start the assembly of the cake. Lay flat one of the biscuit strips, cover with pastry cream, and repeat until all layers and pastry cream is used. Cover the sides and the top of the cake with the cream as well. Put it in fridge to set. In the meantime, melt the chocolates with the cream in a saucepan. Leave aside to set for about 1-2 minutes. Top the cake with the ganache. Once the cake is fully cooled cut into neat squares. Keep the cake refrigerated. Take out 15 min before serving.