For the banana coconut muffins, first separate the eggs. Beat the egg whites until stiff and then, in a separate bowl, cream together the melted butter, sugar, vanilla sugar and egg yolks.
Then mash the bananas and stir them into the sugar-yolk mixture. Now cut the cooking chocolate into chips and stir into the mixture with the coconut flakes, baking powder and flour.
Finally, mix the beaten egg whites with the rest of the mixture and fill the muffin tins 3/4 full. Bake at 160 °C for about 20 minutes and eat warm or cold.