Knead flour, butter in flakes, sugar, vanilla sugar, salt, vinegar and 6 tablespoons of cold water first with the dough hooks of the hand mixer, then with your hands to a smooth dough. Press dough flat, wrap in foil and let rest for about 1 hour.
Meanwhile wash the apricots, quarter them and remove stones. Cut the vanilla pod lengthwise and scrape out the pulp.
Roll out the dough on a floured work surface until round (approx. 37 cm Ø). Cut out a circle (approx. 35 cm Ø). Place on a baking tray lined with baking paper. Spread the apricots on the dough, leaving a rim of about 5 cm wide.
Wavy fold over the edge. Boil up apricot jam with schnapps, vanilla pod, vanilla pulp, lavender flowers and cardamom. Pour over the apricots. Mix egg yolk with 3 tbsp. water and brush the rim with it.
Bake in the preheated oven (electric range: 200 °C/ convection oven: 175 °C/ gas: level 3) on the middle shelf for 30-40 minutes. Remove from oven and let cool on a cake rack. Then chill for 2-3 hours until the jam is firm.
Semi-stiff whipped cream tastes good with it.