Drain plums, let them drain well and dab dry. Cream fat, salt, 1 packet of vanilla sugar and sugar with the whisk of the hand mixer. Stir in the eggs one by one. Mix flour, baking powder and 4 teaspoons of cinnamon. Alternately stir in yoghurt. Carefully fold in plums.
Place 1 paper sleeve in each of the recesses of a muffin tin (12 recesses). Spread the dough evenly with a tablespoon. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for 35-40 minutes. Remove the muffins from the oven and let them cool down on a grid. Whip the cream and egg liqueur until half stiff, while pouring in 1 sachet of vanilla sugar. Place a cream topping on each muffin and dust with 1 teaspoon of cinnamon
45 minutes waiting time