For the sponge cake with gooseberries, sprinkle the sponge cake with rum and place in a greased baking dish. Clean the gooseberries and let them soften in a pot with the wine for about 10 minutes. Drain and then spread the berries evenly on the biscotti.
Separate the eggs and beat the whites to snow. Mix the egg yolks with the flour and then fold in the snow. Spread the cream evenly on the gooseberries and bake in a preheated oven at 175 °C for about 60 minutes.