Grease a box form (25 cm long; 1 1/4 l capacity) and line it with parchment paper. Melt 300 g fat, cool down a little. Stir eggs, sugar and vanilla sugar until creamy. Stir in cocoa. Add warm fat in a thin stream while stirring continuously
Chill approx. 5 tablespoons of chocolate mixture for decoration. Stir the almonds into the rest of the mixture. Place the biscuits side by side in the middle of the mould. Fill 1/6 of the chocolate mixture over the whole surface up to the edge of the mould and smooth it down. In the same way, alternate 5 more layers of biscuits and 5 more layers of chocolate. Chill for about 5 hours
Pull parchment paper from the cake. Roughly chop the chocolate coating. Break 100 g of fat into cubes or chop coarsely. Melt both together in a hot water bath while stirring constantly. Cool down a little. Coat the cake with it and dry. Melt the rest of the chocolate mass in a hot water bath. Pour into a freezer bag, cut off 1 small corner. Decorate the cake with it. Chill overnight.