Beat eggs with butter, sugar and vanilla sugar until foamy. Stir in flour, cornstarch and baking powder.
Pour 1 tbsp. batter into each well of the greased muffin tin, top with 1 tsp. Nutella and finish with 1/2 tbsp. batter.
Bake the muffins at approx. 175 °C with circulating air or level 3 with gas for 15 – 20 minutes. Leave to cool in the tin for about 10 minutes and lift out or turn out.
Preparation Tip:
Instead of Nutella, you can also use a homemade nougat cream for the muffins, for example.