Preheat the oven to 160°C/ 320°F. Draw 6 circles of 22 cm/ 8.5 inches diameter on 6 sheets of baking paper.

Separate the eggs. Beat the egg whites until stiff, add half of the confectioner's sugar (50 g/1.8 oz), and continue beating until the egg whites are stiff and glossy.

Melt the butter in a small pan and let it cool until you beat the egg yolks.

Beat the egg yolks and the remaining confectioner's sugar (50 g/1.8 oz) in another bowl.

Add the egg whites to the egg yolks and incorporate them carefully. Add the melted and cooled butter to the mixture and incorporate. Fold in the flour.

Weigh the batter into another bowl. Divide the quantity into 6 equal portions.

Place one piece of baking paper with the circle on it on a baking tray. Spread one portion of the batter on the circle you drew on baking paper. Bake for 10-11 minutes or until golden. Repeat with the remaining 5 batter portions. Let them all cool completely.

Take the butter out of the fridge and let it come to room temperature.

Beat the eggs, the icing sugar, the vanilla sugar, and the salt in a double boiler (bain-marie) until it thickens slightly.

Take the mixture off the heat and continue beating it until it cools slightly. Stir from time to time.

Melt the chocolate in a double boiler (bain-marie) as well. Let it cool slightly and add it to the egg mixture. Incorporate well.

Beat the butter (at room temperature) in a bowl until creamy. Add the unsweetened cocoa powder and incorporate.

Add the chocolate mixture to the butter one tablespoon at a time and mix thoroughly in between.

Prepare the things needed to spread the caramel on the cake and cut the caramel layer.

Make the caramel: Place sugar, vinegar, and butter in a pan. Let it start to caramelize, and then start stirring gently.

Take the caramel off the heat and quickly spread it on the chosen cake layer using the long buttered spatula. Work very quickly!

Immediately start cutting the caramel cake layer into 12, 14, or 16 slices.

Keep some buttercream for covering the side of the cake and for decorating it with rosettes. Divide the rest into 5 equal portions and spread each portion evenly on each of the remaining 5 cake layers.

Place the first cake layer on a cake platter and arrange the following cake layers on top of each other to form the torte.

Use a little of the remaining buttercream to cover the sides of the cake nicely. Sprinkle the sides with toasted almond flakes or hazelnut brittle.

Place the remaining buttercream into a piping bag and pipe rosettes of buttercream around the top edge of the cake.

Arrange the caramel wedges at an angle on top of the piped rosettes.

Chill the cake before serving.