Work the flour, butter, sugar, vanilla sugar, salt and cinnamon into sprinkles using the dough hook on the hand mixer.
Grease a 26 cm diameter springform pan well. Fill in 2/3 of the crumble and press it down with your hands on the bottom.
Drain the apricots well in a colander. Wash the lemon with hot water and dry it. Rub the peel and squeeze the lemon.
Stir 150 g butter until foamy. Add sugar, vanilla sugar, lemon juice and lemon zest and stir. Gradually stir in the eggs, then add the quark and pudding powder and stir well. Spread the fruit halves on the crumble base with the cut surface facing down. Pour the quark cream on top and smooth it out with a spatula. Spread the remaining crumble dough evenly over the quark.
Bake in the preheated oven at 180 degrees for approx. 50 minutes, then leave to rest for 10 minutes in the switched off oven.
Let the cake cool down and carefully remove it from the mold. Sprinkle with powdered sugar.