If you have trouble mixing the frosting together, try adding just a bit of milk - it will be a lot easier!
125.0g Flour25.0g Butter150.0g Sucker 1,5 egg 1,5 teaspoon baking powder1/2tsp Vanilla sugar0.1l Milk For the filling62.0g Blueberries1/2 Banana1/2tsp Cocoa powder For the cocoa frosting (banana muffin)20.0g Butter125.0g Icing sugar6.0g Cocoa For the vanilla frosting (blueberry muffin)62.0g Butter125.0g Icing sugar1/2tsp Vanilla extract