Beat the butter and preserving sugar until frothy. Stir in the eggs.

Mix the flour and baking powder, sieve over it and stir everything together well. Fold in the quark.

Prepare the fruit accordingly, cut into small pieces and fold into the dough.

Pour the dough into a lightly greased springform pan (sprinkled with breadcrumbs if necessary), smooth it out and bake in a preheated oven at 180 ° C for about 60 minutes.

Let the quark cake cool in the pan.