Prepare the muffin tin. Place the paper baking cases in the tray or grease the indentations. Preheat the oven to 180 ° C.
Mix the butter with the eggs and sugar as well as the vanilla sugar. Add the yogurt. Then gradually add the flour and baking powder. Mix everything into a dough. Then fold in the blueberries.
Pour the dough into the molds, then bake at 180 ° C in the middle of the oven for 20-25 minutes. Let rest in the baking tray for 5 - 10 minutes.