Select the blueberries, wash and drain well. Mix flour, salt, sugar, vanilla sugar and baking powder in a mixing bowl. Add the egg, yoghurt, milk, oil, cinnamon and nutmeg and work into a smooth dough with the dough hooks of the hand mixer. Carefully fold in blueberries. Grease well the recesses of a muffin tray (with 12 recesses of 7 cm Ø each) and fill each with 3/4 of the dough. Bake in a preheated oven (electric: 200 °C/ gas: level 3) for approx. 30 minutes until golden brown.
Let cool slightly on a cake rack. Lift the still warm muffins out of the baking tray recesses and place them in paper cups. Heat the jam in a saucepan and coat the muffins with it. Sprinkle with sugar crystals and serve in a basket. Serve with vanilla ice cream. Makes 12 pieces