Heat the fat and add cold milk. Remove the pot from the stove. Put flour in a bowl. Add salt, egg, lemon zest and sugar, except for a tablespoon. Crumble yeast and mix with remaining sugar.
As soon as the yeast becomes liquid, add to the flour. Add the lukewarm milk-fat mixture while stirring. Work well with the dough hooks of the hand mixer. Cover and leave to rise in a warm place for 30 minutes.
In the meantime, melt the fat for the hazelnut glaze in a pot. Add sugar and vanillin sugar and dissolve in it while stirring. Add cream. Stir in the hazelnut flakes, let the mixture cool down.
Drain the gooseberries. Spread the yeast dough into a greased fat pan of the oven and let it rise for another 15 minutes. Cover with gooseberries. Spread hazelnut icing on top. Bake in a preheated oven (electric: 175 °C/ gas: level 2-3) for 25 to 30 minutes.
Immediately sprinkle with sugar crystals and leave to cool on the baking tray. To serve, thaw ice, add cinnamon and stir until creamy. Serve with gooseberry cake. Makes 24 pieces.