Cream 125 g butter, salt, vanillin sugar and sugar with the whisk of the hand mixer. Stir in the eggs one by one. Mix flour and baking powder and stir in. Finally fold in 4 tablespoons of crumble
Pour the dough into a piping bag, cut off the tip. Place the waffle cup on a baking tray and fill with dough up to approx. 1 cm below the rim. Bake the wafer cups in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: see manufacturer) for approx. 10 minutes until golden brown. Remove the tray from the oven and let the wafer cups cool down
Stir 75 g butter and icing sugar until light and creamy. Carefully stir in the sour cream. Spread the cream on the muffins and sprinkle with remaining crumbles. Place a chewing gum ball on each muffin and chill until serving
Waiting time approx. 45 minutes