Grease a springform pan (26 cm Ø; approx. 8 cm high). Chop the chocolate, melt it in a hot water bath and let it cool down. Knead 250 g flour, cocoa, 50 g sugar, 1 pinch of salt, 1 egg, 125 g butter in pieces and liquid chocolate first with the dough hooks of the hand mixer and then briefly with your hands until smooth. Cover the dough and chill for about 30 minutes
Wash the cherries and, except for some for decoration, remove the stalks and stones
Roll out the dough on a little flour and make it round (about 30 cm Ø). Put it into the form, pressing 2-3 cm up at the edge. If necessary, cut straight with a dough wheel. Put it in a cold place
Mix 100 g butter and 125 g sugar until creamy. Stir in 4 eggs individually. Stir in quark, cream and pudding powder. Spread into the mould. Spread cherries on it and press a little bit into the cheese mixture
Bake in the preheated oven (electric oven: 175 °C/circulating air: 150 °C/gas: level 2) for about 1 1/4 hours. Leave to cool in the mould
Warm the jam. Spread on the cake. Chill for about 15 minutes. Dust the edge with icing sugar and decorate with the remaining cherries