Grease the springform pan. Works well with a piece of kitchen paper or a brush. This way the cake can later be released from the mould in a relaxed manner.
For the shortcrust pastry base, put flour, 60 g butter in pieces, 75 g sugar, 1 pinch of salt and 1 egg in a bowl. First mix everything briefly with the dough hooks of the mixer, then quickly knead it with your hands to a smooth dough.
Form the dough into a ball, wrap in cling film and place in the refrigerator for approx. 30 minutes. Preheat the oven (electric cooker: 180 °C/circulating air: 160 °C/gas: see manufacturer).
For the quark mixture, melt 250 g butter in a saucepan. Let cool slightly. Then whisk 200 g sugar with the whisks of the mixer until foamy. Stir in the eggs one after the other until you get a creamy mixture.
Then add the quark in portions to the sugar and egg mix. Stir in loosely with the whisks of the mixer. Caution: Stir at lowest speed, as the mixture becomes more liquid and splashes. Mix vanilla custard powder and baking powder and stir into the quark mixture.
Wash the lemon hot, grate dry and finely grate the rind with a kitchen grater. Then halve the lemon. Squeeze the juice out with one hand and drizzle it onto the curd mixture with the fingers of the other hand.
It's the easiest way to catch the pips.
Place the springform pan on a wet kitchen towel. That way the mould won't slip away. Roll out the dough on the mould base with a cake roll approx. 1 cm thick until it is close to the edge of the mould. Then pull the dough to the edge with your fingers.
Place the rim of the springform pan on the top. Prick the dough several times with a fork. Why? So that the trapped air under the dough can escape easily and no bubbles form.
Pour the curd mixture onto the shortcrust pastry and smooth it down evenly with a dough scraper. Bake in a hot oven for 50-60 minutes.
After approx. 10 minutes, remove the cake from the edge of the mould with a knife so that the surface does not crack so hard. Continue baking. After 25 minutes cover the cake with aluminium foil and continue baking - otherwise it will be too dark.
Leave to cool at the end of the baking time.