Drain the cherries on a sieve and collect the juice. Stir approx. 100 ml juice and starch until smooth. Boil up the rest of the juice, amaretto and 2 tbsp. sugar. Stir in the starch and simmer for about 2 minutes.
Fold in the cherries. Let the compote cool down.
Break the chocolate into pieces and melt in a hot water bath. Mix mascarpone, quark, 4 tablespoons sugar and vanilla sugar. Whip cream until stiff and fold into the mascarpone cream. Fold about half of the liquid chocolate in streaks into the cream.
Spread a thin layer of cream in a mould (approx. 15 x 25 cm; approx. 7 cm high). Place approx. 100 g brown cakes next to each other on top. Spread half of the compote on top. Cover with half of the remaining cream.
Drizzle some chocolate over it. Pile the rest of the brown cake, the rest of the compote and the rest of the cream on top of it. Drizzle the rest of the chocolate on top. Spread loosely with a spoon. Cover at least.
Chill for 4 hours, preferably overnight.