Pre-Heat oven to 175 Degrees. Mix together: eggs, sugar and vanilla sugar until you get a smooth mixture. Add melted butter, milk and lemon skin. Mix together and then add flour, salt and baking powder at the end. Mix again and then add your choice of berries.
Fill the muffin forms for 2/3 (they will grow a lot in the oven) and then place in the oven for 20 minutes! When ready you can have fun decorating your muffins, I used chocolate, sugar flowers and much more. EASY and YUMMY :)