How to cook
Beat the egg whites and sugar to snow, then while beating nonstop, add the egg yolks 1 by 1. Add the flour, while stirring with a silicone spatula, then add the flour with baking powder as well. Put baking paper in a 9 1/2″ (24 cm) diameter form with removable sides, pour in the mixture and bake at 350°F (175 °C) until your toothpick comes out dry.
Once cooled, cut the baked cake layer into 3 separates ones with a sharp knife.
Put 1/2 the milk with the sugar to boil. To the other 1/2, add the flour and starch. To the hot milk, add the mixture with the dissolved flour. Stir with a whisk until you obtain a thick milk cream. Leave it aside until fully cooled. Mix the softened butter with the prepared milk cream and beat with a mixer.
Caramelize the sugar and add the nuts. Pour it into a tray. Wait for it to cool completely, cover with a sheet of thick plastic and mash it finely (or use a blender).
Beat 3 4/5 cups (900 ml) cream with the sugar to soft tips.
Heat up the cream, without boiling, add the sugar, crumbled white chocolate and the butter. Stir until homogeneous.
Start assembling the cake, place the 1st layer and syrup it with 1/3 of the syrup, smear all of the milk cream, then sprinkle generously with caramel on top.
Place the 2nd layer, 1/3 of the syrup and part of the cream mixture. Sprinkle generously with caramel again. Place the 3rd layer and syrup with the rest of the syrup.
Use the rest of the cream mixture to make walls to prevent the chocolate topping from leaking out - it needs to be slightly cooled.
To make the brown lines, melt the dark chocolate in a water bath, pour it into a pastry bag and spray out horizontal lines. Slide a sharp knife immediately across them, alternating between up and down.