Have all the ingredients ready. Preheat the oven to 175 ° C.
Separate the 4 eggs and beat the egg whites with 60g sugar until stiff and set aside. Put the egg yolks, butter or margarine and the remaining sugar with vanilla sugar in a second bowl and whisk until creamy. Now add the baking powder and, if you want, some lemon juice. Mix briefly, then add the ground hazelnuts and buckwheat flour. Then stir in the roughly grated apples and fold in the egg whites. Spread the batter on the molds of the greased muffin sheets, or in paper cases or in paper cases in the muffin sheet. Now the muffins are baked for about 15-20 minutes, stick test. The buckwheat muffins can be sprinkled with powdered sugar after baking or covered with a chocolate icing.