Mix all ingredients for the shortcrust pastry at room temperature, roll out a little, place in a springform pan lined with baking paper, spread the pastry over the entire base with your fingers, prick several times with a fork and refrigerate for at least 30 minutes.
Then bake in the preheated oven (200 °) for about 10 minutes.
Prepare the sponge cake during this time:
Beat the egg with the hot water and sugar until thick and frothy. Sift the flour, cornstarch and baking powder over it and fold in carefully with a whisk.
Take the pan out of the oven, spread 3-4 tablespoon warmed jam on the pre-baked shortcrust pastry. Spread the sponge cake on top and bake for another 10 minutes.
Remove from the mold and let cool down, cover with fruit and top with cake icing.