Preheat oven (electric cooker: 175°C/circulating air: 150°C/gas: see manufacturer). Separate the eggs. Mix quark, 50 g sugar, vanilla sugar, egg yolk and lemon curd with the whisks of the mixer. Stir in sauce powder.
Beat the egg white and 1 pinch of salt until stiff and fold in with a whisk.
Grease four ovenproof cups or moulds (each containing approx. 1/4 l). Pour in the cheesecake mixture to approx. 1 cm below the rim. Bake in a hot oven for 20-25 minutes. Remove from the oven and let it cool down for about 1 hour.
Sprinkle each surface with 1 teaspoon sugar. Caramelize with a kitchen gas burner or in the oven under the hot grill for 1-2 minutes until golden brown.