Melt 100 g butter. Roughly chop the chocolate. Mix 200 g flour, 1 pinch of salt, 100 g sugar and 1 packet of vanillin sugar. Add the butter and work into crumbles using the dough hooks of the hand mixer.
Add the chocolate and knead lightly with your hands. Chill for about 30 minutes. Wash the cherries, remove the stalks and stone them. Mix 250 g butter, 250 g sugar, 1 packet of vanilla sugar and 1 pinch of salt with the whisk of the hand mixer.
Stir in the eggs one by one. Mix 200 g flour, starch and baking powder and stir in. Grease the fat pan of the oven (32 x 39 cm). Fill in the sponge mixture and smooth it down. Spread cherries on top.
Boil the potatoes, peel them and let them cool down. Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for 35-40 minutes. Remove from the oven, allow to cool on a cake rack and cut into pieces.