Pit the cherries and rinse well.
Cream the butter with the sugar and mix in the eggs one at a time. Finally, fold in the flour, nuts, chocolate pieces and the baking powder.
For the crumble, crumble the cold butter with the sugar, flour and cocoa until lumps form.
Butter a springform pan (26 cm diameter) and dust with a little flour. Preheat the oven to 170 °C.
Pour the dough into the pan. Spread the cherries on top and sprinkle with the crumbles.
Bake the cake in the hot oven for 45-50 minutes.