Place 1 paper cups in the recesses of each muffin tray (for 12 pieces). Mix 3 tbsp. berries and jam
Beat the egg, sugar, vanillin sugar and 1 pinch of salt for about 5 minutes until creamy. Gradually fold in the oil and kefir. Mix 275 g flour, baking powder and baking soda and stir in briefly. Mix the rest of the berries unfrozen with 1 tbsp. flour and fold into the dough. Pour into the moulds
Bake in the preheated oven (electric oven: 200 °C/circulating air: 175 °C/gas: level 3) for about 20 minutes. Spread the berry and jam mixture on top. Continue baking at the same temperature for about 5 minutes. Leave to cool for about 10 minutes. Remove from the baking tray and allow to cool completely. Dust with icing sugar before serving