Heat up the milk to Luke warm.
Crumble the yeast in the milk. Stir with a spoon until it's lump free.
In a bowl mix the flour, sugar, and vanilla sugar.
Add the eggs and the milk, and knead the dough well.
Let the dough rest for 30 minutes.
Add the soft butter and knead it well by hand.
Add the pearl sugar and mix well.
Divide the dough in small balls of 60 grams each. Let the dough rest for 15 minutes.
Roll the dough balls in icing sugar and cook on the waffle iron for 2 minutes