For the compote, cut the vanilla pod lengthwise and scrape out the pulp. Coarsely grate the marzipan. Boil up apple juice, vanilla pod and 50 g sugar in a pot. Add marzipan and dissolve in it. Rinse blueberries, stir in, bring to the boil and simmer for about 2 minutes. Let the compote cool down.
In the meantime soak the gelatine. First mix sour cream, 2 tablespoons of sugar, vanilla pulp and cream, then beat until stiff. Squeeze the gelatine, dissolve in a small pot. Stir in 2 tbsp. cream, then stir into the rest of the cream. Finely puree half of the compote, stir into the cream in streaks. Chill the cream for about 15 minutes.
Amarettini crumble. Remove the vanilla pod from the compote. Arrange compote and cream and sprinkle with amarettini.