For the short pastry, put flour, butter in flakes, egg, 100 g sugar, vanilla sugar, salt and baking powder in a mixing bowl and knead with the dough hooks of the hand mixer. Then knead with your hands to a smooth dough.
Grease a fruit base mould (24 cm Ø). Sprinkle the wavy edge with flaked almonds. Press the dough evenly flat into the mould. Prick several times with a fork. Chill for 15 minutes. Then bake in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for 18-20 minutes.
Then remove from the oven, place on a cake rack and allow to cool slightly. Turn out of the mould and let it cool down. In the meantime, wash the grapes, pluck them from the panicles and let them drain.
Coat the cooled soil with Lemon Curd, spread grapes evenly on top. Mix cake glaze powder, 30 g sugar in a pot. Gradually add 250 ml water and stir until smooth with a stirring spoon.
Bring to the boil briefly while stirring. With a tablespoon, spread evenly from the centre over the grapes. Allow to set. Decorate with lemon balm. Serve with whipped sour cream.