First stir the butter, sugar, vanilla sugar, lemon juice and eggs on the highest setting for about 1 minute until it becomes a creamy mixture. Stir in the yogurt, flour and baking powder. Finally stir the pudding powder briefly into the mixture and pour it into a greased springform pan, spread the cherries on top and bake at 200 degrees for about 40 minutes. If the cake gets too dark, simply put aluminum foil over it.