For the dough, beat the eggs, sugar and vanilla sugar with a mixer until creamy. Then stir in the softened butter, low-fat quark and pudding powder. Line a muffin tin with 12 molds and distribute the mixture in it.
For the crumble, knead the flour with the butter, sugar and cocoa and spread over the muffins.
Bake the muffins for about 20-30 minutes until they are lightly brown.