Beat the eggs with the butter, sugar and vanilla sugar until frothy. Mix the flour with the baking powder and add to the foam mass. Mix everything together well. Add cocoa powder, lemon juice and a pinch of salt and process to a creamy mass. Now fold the chocolate sprinkles into the mass. Put everything in a greased form.
For the crumble, all the ingredients are simply kneaded together and distributed over the cake mixture (you can also make more crumble, depending on the size of the cake and taste).
Now everything is baked in the oven at 180 - 200 ° C for about 45 - 50 minutes (make a stick test). Let the cake cool down a little and dust with powdered sugar.