Crumble the amarettini. Wash the grapes, pluck them and cut them in half if necessary.
Beat the egg whites until stiff, sprinkling in 1 tablespoon of sugar. Mix the mascarpone with quark, milk, 1 tablespoon sugar, vanilla sugar and lemon zest until creamy.
Fold in the egg whites.
Now layer the crumbled amarettini (except for 1 tablespoon of it) and grapes in a bowl, alternating with the mascarpone cream. Finally, decorate with whole amarettini and the remaining crumbled amarettini.