Grease a springform pan (26 cm Ø; approx. 8 cm high) and dust with flour. Mix flour, baking powder, 50 g sugar, 1 packet of vanilla sugar and 1 pinch of salt. Add 1 egg yolk, butter in pieces and 1-2 tbsp. cold water.
First knead everything with the hand mixer, then briefly with your hands until smooth.
2⁄3 Roll out the dough on a little flour until round (approx. 26 cm Ø) and place on the bottom of the mould. Form the rest of the dough into 2 rolls (each approx. 40 cm long). Place inside on the edge of the mould and press up the edge by approx. 2 cm.
Prick the pastry base several times with a fork. Chill for about 30 minutes.
Drain the apricots. Mix quark, 150 g sugar, 1 packet of vanilla sugar and 5 eggs. Stir in pudding powder. Fill into the mould and cover with apricots.
Bake in a preheated oven (electric cooker: 175 °C/circulating air: 150 °C/gas: see manufacturer) 1 1⁄4-1 1⁄2 For hours. Then leave to cool in the switched-off oven with the oven door half open for approx. 10 minutes.
Remove from the oven and let it cool down in the springform pan.
Heat the jam and pass through a sieve. Spread the apricots. Dust the top of the cake with icing sugar. Whipped cream tastes good with it.