Line a shallow bowl with ladyfingers and soak with coffee and amaretto. Beat the egg yolks, vanillin sugar and icing sugar until creamy with the whisks of the hand mixer. Stir in the mascarpone bit by bit. Halve the cream. Sift the cocoa onto one half and stir in. Fill the creams into two piping bags without spout and squirt them in two strips on the lady fingers.
Chill for at least 2 hours. In the meantime, chop the light and dark chocolate coating coarsely and melt separately in a hot water bath. Spread the couverture on a baking tray and refrigerate for about 1 hour. Cut Tiramisu into 8 pieces. Use a spatula to push the couverture into rolls. Decorate Tiramisu pieces with it