Grind Cantuccini in the universal grinder. Wash and clean the gooseberries and drain well. Stir jam until smooth. Mix in gooseberries and 25 g sugar. Mix butter, 75 g sugar, salt and vanillin sugar.
Knead in sour cream, flour and baking powder. Roll out into a circle (approx. 28 cm Ø) on a well floured work surface. Place in a greased tart tin (24 cm Ø), press down the base and edge.
Sprinkle the cantuccini on the floor and spread gooseberries on top. Bake in the preheated oven (electric range: 200 °C/ convection oven: 175 °C/ gas: level 3) on the lower rack for 40-45 minutes. Remove from the oven and allow to cool on a cake rack.
Remove the rim from the mould. Whipped cream tastes good with it.