For the cream, warm the cream lukewarm. Chop the mocha chocolate and dissolve in it. Chill the cream for about 3 hours. In the meantime, separate the eggs for the base. Beat the egg white and 3 tablespoons of cold water until stiff. Let sugar trickle in. Stir in egg yolk. Mix flour, cornstarch and baking powder, sieve and carefully fold in.
Line the bottom of a springform pan (26 cm Ø) with baking paper. Fill in sponge cake mixture and smooth it down. Bake in the preheated oven (electric: 175 ° C/ gas: level 2) for about 20 minutes. Then let it cool down a little. Loosen the edge with a knife. Let the cake base cool down completely on a cake rack. Then cover with a cake crust. Sprinkle with coffee. Grate the mocha chocolate. Put 1 tablespoon aside for decorating. Sprinkle the rest of the chocolate on the cake base. Whip the cold chocolate cream with the whisk of the hand mixer and spread it on the base. Chill for another 30 minutes. Whip cream and vanilla sugar until stiff. Spread on the cream.
Grate the mocha chocolate. Put 1 tablespoon aside for decorating. Sprinkle the rest of the chocolate on the cake base. Whip the cold chocolate cream with the whisk of the hand mixer and spread it on the base. Chill for another 30 minutes. Whip cream and vanilla sugar until stiff. Spread on the cream. To decorate, chop white couverture and melt in a hot water bath. Spread thinly on a board (not wood) and leave to cool. Use a spatula to form delicate rolls. Sprinkle cake with white rolls and retained mocha chocolate. Melt the sugar until golden brown. Use two forks to make fine threads. Decorate the cake with them. Makes about 12 pieces
To decorate, chop white couverture and melt in a hot water bath. Spread thinly on a board (not wood) and leave to cool. Use a spatula to form delicate rolls. Sprinkle cake with white rolls and retained mocha chocolate. Melt the sugar until golden brown. Use two forks to make fine threads. Decorate the cake with them. Makes about 12 pieces