Drain the cherries (use the juice for other purposes). Grease an angular springform pan (24 x 24 cm; alternatively round, 26 cm Ø) and dust with flour. Preheat oven (electric cooker: 175 °C/circulating air: 150 °C/gas: see
For the dough, whisk 250 g butter, 225 g sugar and 1 pinch of salt with the whisks of the mixer for about 5 minutes until foamy. Stir in the eggs one after the other. Mix 250 g flour and baking powder. Stir into the egg-sugar mixture.
Smooth half of the dough in the form. Chop 50 g chocolate coating. Dissolve coffee in 3 tbsp. hot water. Stir cocoa and chopped chocolate coating into the rest of the dough. Spread the dark dough on the light dough.
Stir once with a tablespoon handle (marble). Spread cherries on top. Bake in a hot oven for 35-40 minutes. Let it cool down.
For the cream, mix 5 tablespoons of milk, vanilla sugar, 1 tablespoon of sugar and pudding powder. Bring the rest of the milk to the boil, stir in the pudding powder. Simmer for about 1 minute while stirring. Pour into a bowl.
Cut 80 g butter into pieces and stir into the hot pudding until it has melted. Cover the pudding with foil and let it cool down to room temperature.
Cream 170 g butter and icing sugar with the whisk of the mixer for about 5 minutes. Stir in vanilla pudding by the spoonful. Spread the butter cream with a tablespoon on the cake until slightly wavy.
Chill for at least 2 hours.
Remove the cake from the tin and cut into cubes of approx. 4 x 4 cm. Chill again briefly. Chop 200 g chocolate coating and melt in a hot water bath. Melt the cake glaze in a bain-marie according to the package instructions.
Mix with chocolate coating. Spread with a spoon over the Danube waves. Let the glaze dry.