Beat the eggs with the mixer until creamy. Add sugar with vanilla sugar. Stir in the soft butter, flavor and sour cream. Stir in the flour mixed with baking powder. Depending on the consistency, you can use more flour or add ground almonds. Finally, peel and grate the apple and fold it into the batter.
Then bake in the waffle iron as usual. These waffles are usually a little thicker and the dough should be spread lightly in the iron so that the amount is evenly distributed