For the dough, mix the butter, which is at room temperature, with all the ingredients except cocoa to make a dough that is difficult to tear. If you use a hand mixer, first stir the butter, sugar and eggs until frothy and gradually add everything else. Line a 26 cm springform pan with parchment paper. Grease the inner edges with a little oil.
Spread half of the dough on the base. Stir the cocoa into the other half and spread on the first dough. Spread the drained cherries on top. Place the cake in the oven on the middle rack at 160 ° upper and lower. Bake the bottom heat for approx. 40 minutes. Chopstick sample. Take out and let cool down for a while.
In the meantime, cook the pudding. To do this, bring the milk, sugar and vanilla pod to the boil. Remove some milk and use it to stir the cornstarch until smooth. Pour into the vanilla milk. Add a pinch of ground saffron. When everything has thickened, remove the saucepan from the heat immediately and let it cool down. Stir in between so that no skin forms.
The pudding is then spread on the cake. For the topping, dissolve the couverture in a hot water bath. The water must not boil, otherwise the chocolate will curdle. Mix the sour cream with the chocolate and then spread everything on the custard layer of the cake. When the casting has cooled down a little, scratch waves with a fork. Chill everything for a few more hours and then enjoy your meal.