For the dough, mix flour, sugar, vanillin sugar, baking powder and 1 pinch of salt. Add butter in pieces and 6 tablespoons of ice-cold water. Knead first with the dough hooks of the hand mixer and then quickly with your hands to a smooth dough.
Wrap in foil and chill for about 1 hour.
Grease 6 cake tins (approx. 12 cm Ø; or see tip on page 109) and dust with flour. Roll out the dough between two layers of baking paper. Cut out 6 circles (each approx. 16 cm Ø). Place the dough in the baking tins and press the rim.
Pierce the floor.
Preheat oven (electric cooker: 175 °C/circulating air: 150 °C/gas: level 2). Squeeze limes, 1⁄8 l Measure the juice. Mix eggs, 75 g sugar, cream and lime juice.
Pour into the tarts. Bake in the hot oven on the lowest shelf for 30-35 minutes. After about 10 minutes baking time, sprinkle each tart with 1 tablespoon of sugar.