Preheat the oven to 175 ° C top / bottom heat. Cover a tray with baking paper.
Peel, quarter, core and dice the apples. Squeeze the lemon and mix the juice with the apples.
Mix the butter with sugar until frothy. Stir in the egg, then add the quark and milk. Mix the flour with baking powder and salt and knead into the dough. Finally fold in the apple cubes evenly with a spatula.
Put the cinnamon sugar in a small bowl. Separate 12 rolls from the dough with 2 tablespoons and roll them in cinnamon sugar.
Place the rolls on the baking tray and bake in the middle of the oven for 25 minutes.