Stir the butter until foamy, sprinkle with sugar and add the eggs one after the other. Sift the flour with the baking powder and add spoon by spoon. Now stir in cocoa, cinnamon and vanilla sugar. If the dough is too firm, add a little milk (maximum 3 tablespoon). Then mix in the almonds and walnuts and fold in the apples.
Grease a springform pan, sprinkle with breadcrumbs, add the dough and smooth out well. Tap under the cake with the flat of your hand so that the dough is evenly distributed.
Bake the cake for about 60 minutes and, if you like, sprinkle it with powdered sugar after it has cooled down.