To prepare the cherry cupcakes, set aside 6 Leibniz cocoa cookies, place the remaining cookies in a plastic bag, seal and make fine crumbs with a rolling pin.
Place sour cherries in a sieve to drain, collect juice and measure out 125 ml cherry juice. Line 1 muffin tin with 12 muffins with paper baking cups. Preheat oven, top/bottom heat about 180 °C, hot air about 160 °C.
For the batter, cream butter or margarine with a mixer until fluffy. Gradually add the sugar.
Stir in the eggs for ½ minute at a time. Mix flour with baking powder, baking soda and the cocoa cookie crumbs and stir into the egg mixture alternately with the milk. Fold in the chocolate.
Pour half of the batter into the paper baking cups. Spread the cherries (leave 12) on top and cover with the remaining batter.
Place the muffin tin on the rack in the preheated oven. Bake for about 30 minutes. After that, place the muffin tin on a cooling rack. Remove the cupcakes from the mold after about 5 minutes and let them cool on the cooling rack.
Meanwhile, combine cherry juice with cornstarch and sugar in a small saucepan with whisk and bring to a boil over medium heat, stirring. Allow the cherry sauce to cool while stirring.
For the topping, whip the mascarpone, whipping cream and powdered sugar with a mixer to a firm cream.
Spoon the mascarpone mixture onto the cupcakes. Top with the