For 8 Watermelon Muffins you need:

³/₄ cup of flour
¹/₂ cup of sugar
50g butter
1 egg
1 teaspoon of baking powder
1 package of vanilla sugar
¹/₂ cup of watermelon juice
red and green food colouring
chocolate chip

oven baking temperature: 180 C°
baking time: ~25min

Instruction:
1. Beat butter, sugar and vanilla sugar together until it becomes creamy
2. Add the egg and continue mixing
3. Mix the flour with the baking powder and add it to the butter-sugar-mixture.
4. Add the watermelon juice and mix everything very well
5. Colour ¹/₃ of the dough with green food colouring
6. You can add a bit of red food colouring to the rest of the dough, add chocolate chip
7. Fill the red dough into the baking cups and top the green dough on it
8. Bake the Muffins for about 25min and let them cool completely on a rack