Mix flour, 75 g sugar, salt and baking powder in a bowl. Add 1 egg and 175 g butter in pieces. Knead first with the dough hooks of the hand mixer, then with your hands to a smooth dough. Cover and chill for approx. 30 minutes
Roll out the dough round (approx. 34 cm ∅) on a work surface dusted with flour. Place the dough in a greased springform pan (26 cm ∅) and press down at the edges
Melt 125 g butter and let it cool down. Mix the quark with 150 g sugar, 2 eggs and pudding powder with the whisk of the hand mixer until smooth. Also stir in lemon juice and butter. Finally, stir in the milk with a whisk. Pour the curd mixture into the mould. Bake in the preheated oven (electric cooker: 175 °C/ circulating air: 150 °C/ gas: see manufacturer) on the 2nd rack from below for approx. 1 1/4 hours
Take the cake out of the oven and let it cool down. Select the blueberries, wash and drain well. Boil up the juice and nectar to 3 tablespoons. Stir the rest of the juice and starch until smooth, bind the juice with it, bring to the boil again. Stir in blueberries and spread on the cake
waiting time approx. 1/2 hours