Separate eggs. Beat the egg whites and 2 tablespoons of water until stiff, adding 125 g sugar. Stir in egg yolks. Mix flour, starch and baking powder and fold in as well. Line a baking tray with baking paper and spread the mixture evenly on top. Bake the sponge cake in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for approx. 10 minutes.
Soak the gelatine in cold water. Remove the tray from the oven and let the sponge cake cool down. Mix mascarpone, milk, vanillin sugar and 100 g sugar. Whip the cream until stiff. Halve the sponge cake. Place a cake frame around one half. Squeeze the gelatine and dissolve. Mix 3 tablespoons of the cream with the gelatine and stir into the remaining cream. Mix coffee and liqueur. Fold the cream first, then the grated chocolate into the cream. Spread 2/3 of the cream on the base and place the 2nd base on top. Sprinkle the coffee on the 2nd cake layer.
Mix 3 tablespoons of the cream with the gelatine and stir into the remaining cream. Mix coffee and liqueur. Fold the cream first, then the grated chocolate into the cream. Spread 2/3 of the cream on the base and place the 2nd base on top. Sprinkle the coffee on the 2nd cake layer. Spread the rest of the cream on top in waves. Chill the cake for at least 1 hour. Remove the cake from the frame, dust with cocoa and cut into 12 pieces
Waiting time approx. 1 hour