Melt 200 g butter, cool slightly. Finely chop 200 g chocolate coating. Dice marzipan. Separate eggs. Mix marzipan, vanilla sugar, salt and egg yolk with a hand mixer until creamy
Beat the egg white until stiff in portions, add sugar. Fold about 1/3 of it into the egg cream. Alternately fold in 250 g flour, liquid butter and another 1/3 of the egg whites. Fold in the rest of the beaten egg white
Spread half the dough on a greased, floured fat pan. Sprinkle chopped chocolate coating over it. Spread the rest of the dough on top. Bake in a hot oven (electric cooker: 175 °C/circulating air: 150 °C/gas: level 2) for 25-30 minutes. Cool down for about 20 minutes. Prick more often, sprinkle with liqueur. Cool down
Coarsely chop 400 g of chocolate coating. Melt in a hot water bath. Cover the cake with the chocolate, allow to dry and decorate. Leave to dry. Cut into small pieces