Grease 12 brioche cups (approx. 9 cm Ø, 3 cm high) or a muffin tray (for 12 pieces). Knead 150 g flour, 50 g sugar, 1 pinch of salt, fat in pieces and 2-3 tbsp. ice-cold water first with the dough hooks of the hand mixer, then briefly with your hands
Roll out the dough on a little flour to a thickness of about 5 mm, cut it out with a ramekin, press the dough into it. Or for a muffin tray, form the dough into a roll and cut into 12 pieces. Form each piece into a ball, roll out round (approx. 11 cm Ø) on a little flour. Line a form with it and press the dough up at the edges. Prick the dough base several times with a fork. Cover and chill for about 1 hour
Bake the tartlets in a preheated oven (electric cooker: 200 °C/circulating air: 175 °C/gas: level 3) for approx. 12 minutes. Allow to cool for approx. 10 minutes, then turn out of the tartlets or tray and cool down
Mix quark, lemon juice, 75 g sugar and vanillin sugar. Whip cream until stiff and fold in. Pour into the tartlets. Place 1 apricot half on each tart. Dust the edges with icing sugar