Mix flour and baking powder. Separate the eggs. Mix egg yolks, 150 g sugar, salt, vanillin sugar, 125 g butter and buttermilk. Carefully fold in the flour mixture. Line the recesses of a muffin tray (12 troughs) with paper cups and spread the dough in them
Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for approx. 25 minutes. Let muffins rest for about 5 minutes. Carefully remove from the tray. Let them cool down
Whisk the egg whites and 125 g sugar with the whisk of the hand mixer on a hot water bath until the sugar is dissolved. Take the mixture down and continue stirring until it has cooled down and forms firm peaks. Gradually add 150 g butter while stirring. Fold in jam. Spread the finished cream over the cupcakes
Waiting time approx. 1 hour