Cut 100 g butter into pieces. Knead flour, butter, 75 g sugar and 1 egg first with the dough hooks of the hand mixer, then with your hands to a smooth dough. Wrap the dough in foil and chill for about 30 minutes. Melt 50 g butter. Mix quark, yoghurt, lemon juice, 3 eggs, 125 g sugar, pudding powder and liquid butter. Roll out the dough on a floured work surface until round (approx. 30 cm).
Grease a tart tin (approx. 26 cm Ø) and line with the dough. Cut off protruding edges or fold inwards and press firmly. Pour the quark mixture into the mould and bake in a preheated oven (electric range: 175 °C/ convection oven: 150 °C/ gas: level 2) for 50-60 minutes. Remove the tart from the oven and let it cool down on a cake rack. Sort the blueberries. Mix the cake glaze and 2 tablespoons of sugar in a saucepan. Add 250 ml cold water and stir until smooth. Add blueberries. Bring the liquid to the boil briefly while stirring (with a wooden spoon), then immediately spread on the tart. Chill the tart for about 30 minutes. Wash the mint, shake dry and pluck the leaves from the stalks, except for 1 stalk.
Mix the cake glaze and 2 tablespoons of sugar in a saucepan. Add 250 ml cold water and stir until smooth. Add blueberries. Bring the liquid to the boil briefly while stirring (with a wooden spoon), then immediately spread on the tart. Chill the tart for about 30 minutes. Wash the mint, shake dry and pluck the leaves from the stalks, except for 1 stalk. Chop the leaves finely and mix with the sugar crystals. Sprinkle Tarte with mint sugar before serving and decorate with the remaining mint.
waiting time approx. 2 hours