Mix eggs, sugar, vanilla sugar and soft fat with the mixer until frothy. Stir in the liqueur, flour, baking powder and cocoa powder. Beat egg whites until stiff and fold in carefully.
Pour the batter into a heart or bundt cake pan. Oven to 200 degrees, circulating air to 180 degrees. Bake the cake for 50-55 minutes.
Let the cake cool down and cover with chocolate icing.
Tip:
If you want to bake the cake without alcohol, replace the liqueur with 150 ml cocoa.