Knead the fat, 300 g flour, 150 g sugar, muesli and 1 pinch of salt into crumbles. Cover and put in a cool place. Drain the cherries, collecting the juice
Stir 100 ml cherry juice and starch until smooth. Bring the rest of the juice to the boil. Stir in the starch, bring to the boil and simmer for about 1 minute, stirring continuously. Fold in the cherries. Mix 175 g flour, baking powder, 50 g sugar, salt and vanilla sugar. Add quark, oil and milk. Knead everything smooth.
Roll out the quark and oil dough on a little flour until round (approx. 30 cm Ø). Put the dough into a greased and flour-sprinkled springform pan (26 cm Ø), press down at the edges. Spread the stewed cherries smooth. Spread crumbles on top. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for about 35 minutes. Let it cool down