Drain the quark, rub through a fine sieve and stir until smooth with 2 tablespoons of brown sugar and the milk. Drain the sour cherries.
Crumble the pumpernickel in a bowl and sprinkle the remaining sugar over it, soak it with the kirsch. Add the grated chocolate and mix everything well.
Layer the mixture in a glass bowl, alternately pour a layer of pumpernickel, then quark and a layer of cherries. Chill the quark in the refrigerator for about 2 hours until eaten.