Mix the butter, egg and sugar until frothy. Mix flour with baking powder and cocoa powder and add. Use the hand mixer to make loose sprinkles. Then press 2/3 of the dough into a greased springform pan (26 cm) as a base and form an approx. 4 cm high edge.
Beat eggs with sugar, vanilla sugar, a pinch of salt and lemon juice until frothy. Stir in the custard powder and quark. Fold the cherries and half of the chocolate sprinkles into the curd mixture. Put on the floor. Spread the remaining dough as a crumble on the quark mixture. Spread the remaining chocolate sprinkles on top. Bake at 175 ° C for about 50 minutes. After baking, let cool in the pan.