Drain the cherries (use the juice for other purposes). Drizzle with 2 tablespoons of kirsch. Coarsely crumble the biscuits and divide into 4 dessert glasses. Drizzle with 4 tsp. kirsch
Beat the sour cream with the whisk of the hand mixer, adding vanilla sugar and sugar. Stir in curd cheese
Spread the cherries and cream on the sponge cake and refrigerate for at least 1 hour, dust with icing sugar and cocoa. Decorate with lemon balm