Separate eggs. Beat the egg whites until stiff, adding 150 g icing sugar. Mix the fat and 100 g icing sugar until creamy. Stir in the egg yolks one by one. Mix flour and baking powder and fold in. Fill the dough into a greased springform pan (26 cm Ø) sprinkled with breadcrumbs and smooth it down.
Bake in a preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for 45-50 minutes.
Let the cake cool in the mould, then remove from the mould. Prick the surface of the cake about 25 times with a spoon handle. Mix coffee and 1/8 litre of liqueur and pour evenly into the cake holes.
Peel off the chocolate coating with a peeler. Whip the cream until stiff, adding cream firming agent and sugar. Spread the cream all around the cake. Sprinkle with the chocolate coating.
Just before serving, sprinkle with 8-10 tablespoons of liqueur.