For the quark and oil dough mix quark, milk, oil, sugar, vanillin sugar and salt. Mix flour and baking powder and knead. Grease a springform pan (24 cm Ø) and press the dough onto the bottom of the springform pan.
For the glaze, roast the hazelnuts and let them cool down. Mix egg yolk, crème fraîche and sugar. Finally fold in the hazelnuts. Spread the hazelnut icing on the dough. Wash and peel the apples, remove the core and cut into slices.
Place apple slices in a fan shape on the glaze. Bake in the preheated oven (electric oven: 200 °C/ gas: level 3) for 25-30 minutes. In the meantime, heat up the jam in a pot and pass it through a sieve.
Spread hot apple tart (apple pieces and edge) with it. Let it cool down. Serve with whipped cream. Makes 12 pieces.