Grease a 12 cup muffin pan. Preheat the oven to 200 ° C.
Beat the eggs until frothy and stir together with the butter, sugar and vanilla sugar until smooth. Sieve the flour, baking powder and cornstarch onto the egg mixture and stir in. Pour 1 tablespoon of dough into each recess of the mold, put 1 teaspoon of Nutella on top and finish with 0.5 tablespoon of batter. Bake the muffins for 15 to 20 minutes, then let cool and lift out.
Note: Nutella sinks to the bottom when baking. Let it cool down well, otherwise the Nutella will stick in the mold. Have never tried the recipe with paper liners so I can`t say if it works.