Grease a springform pan (26 cm Ø; approx. 7.5 cm high) and sprinkle with sugar. Melt 150 g butter at low heat. Mix flour, 100 g sugar, 1 packet of vanilla sugar and 1 pinch of salt. Add liquid butter in a thin stream, kneading it in with the dough hooks of the hand mixer. Then briefly work into crumbles with your hands
Cream 100 g butter, 150 g sugar, 1 packet vanilla sugar and 1 pinch of salt. Stir in the eggs one by one. Stir in curd, mascarpone and semolina briefly
Spread half of the crumble as a base in the mould and press it down, pressing up slightly at the edges. Spread the jam on the dough base. Spread the quark mixture on top. Sprinkle the rest of the crumbles on top, rubbing or pulling between your fingers.
Bake in the preheated oven (electric oven: 200 °C/circulating air: 175 °C/gas: level 3) for about 1 hour. Leave to cool well in the mould. Dust the mascarpone cake with icing sugar