We begin with the cream because the biscotti are ready to use. Put 2/5 cup (100 ml) milk in a cezve or pot to heat up. Break the dark chocolate into it, add 2 tbsp cocoa.
Stir nonstop until the chocolate melts and turns to a thick mixture. Remove from the heat and leave it to cool a bit.
Beat the 4 egg yolks in a water bath as follows: put a small pot with water on the stove to come to a boil. In the water, place a bowl with the egg yolks and beat them with the powdered sugar with a mixer until whitened.
Flavor with 1 packet of vanilla sugar. Add the butter (which has sat at room temperature) in lots, spoon by spoon. Then add the chocolate cream spoon by spoon.
When you're ready to assemble the cake, prepare a bowl of 1 1/5 cups (300 ml) unsweetened milk, pour 1 tbsp rum or cognac in it and dip each biscotti in it briefly.
Arrange 8 biscotti in a suitable plate, after dipping them in the milk, to serve as the base. Apply a layer of the cream on top.
Sprinkle 5 crumbled meringues and 5 crumbled macaroons over the cream. For the next layer, dip each biscotti in the milk and distribute 1 tbsp of the cream over it. Arrange them in a spiral, sticking them next to each other.
Beat the egg whites with a mixer on low speed with a pinch of salt and once it turns to a snowy mixture add 2/5 cup (100 g) sugar. Continue beating to stiff peaks. Add 1 packet vanilla sugar.
Melt 4/5 cup (200 g) sugar in a small container on the stove to obtain a caramel. While still hot, pour the caramel in a thin trickle to the egg whites. Stir to obtain a nice caramel cream.
Cover the entire cake with the egg white caramel cream, spoon by spoon.
Mash the peanut bar with a mallet as it is in the wrapper, so it doesn't spill everywhere. Sprinkle the cake's sides with this peanut glaze.
Decorate with a few small meringues and chocolate truffles.