Mix flour, baking powder, sugar, vanillin sugar, rum, eggs, quark, 125 g butter in small pieces, gingerbread spice, lemon aroma and salt first with the dough hooks of the hand mixer, then knead with your hands to a smooth dough.
Knead chocolate drops underneath. Grease the stollen mould and put the dough into it. Place on a baking tray lined with baking paper and bake in the preheated oven (electric range: 175 °C/ convection oven: 150 °C/ gas: level 2) for 50-60 minutes on the middle shelf.
Take out, fall out of the mould. Let the studs cool down. Melt 100 g butter and spread the stollen with it. Dust with icing sugar.