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. Pour the quark mixture into the mould. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) on the 2nd rack from below for approx. 1 1/4 hours
Beat the egg whites until stiff, gradually adding 150 g sugar. Continue beating briefly until the meringue is shiny. Remove the cake from the oven. Carefully spread the meringue on the cake, leaving about 2 cm free at the edges. Bake in the still hot oven at the same temperature for about 15 minutes. Remove from the oven, let cool off
waiting time approx. 1/2 hours