Heat butter in a pot. Mix flour, 200 g sugar, vanillin sugar and salt in a bowl. Add hot butter and knead into a crumbly dough with the dough hooks of the hand mixer.
Put a good half of the crumbles in a greased springform pan (26 cm Ø) sprinkled with breadcrumbs and press them down to a base. Drain mandarins well on a sieve. Mix quark, 125 g sugar, eggs, pudding powder and lemon zest to a smooth mixture.
Fold in mandarins, place the cheese mixture on the crumble base and smooth it down. Sprinkle with the remaining crumbles and bake in the preheated oven on the lower rack (electric oven: 175 °C/ convection oven: 150 °C/ gas: level 2) for approx. 1 hour.
Carefully remove the finished cheesecake from the edge with a knife and let it cool in the mould on a cake rack. Serve dusted with icing sugar