Put 375 g flour, salt and lemon zest in a bowl. Stir yeast with 2 teaspoons of sugar until smooth. Stir in another 50 g sugar. Add yeast mixture and another 50 g sugar to the flour.
Melt 75 g fat, add milk. Add lukewarm milk-fat mixture and egg to the flour mixture. Knead ingredients with the dough hooks of the hand mixer to a smooth dough. Cover the dough and let it rise in a warm place for about 20 minutes.
Meanwhile clean the gooseberries separately, wash them carefully and drain them well. Melt the remaining fat. Put the rest of the flour, sugar and cinnamon in a bowl. Add melted fat and knead ingredients into crumbles.
Knead the yeast dough well with your hands again. Roll out the dough on a greased baking tray and sprinkle with breadcrumbs. Using a knife, mark a diagonal cross in the dough sheet so that four dough triangles of the same size are formed.
Spread green and red gooseberries alternately in the dough triangles. Sprinkle the crumbles over them. Let the cake rise in a warm place for another 10 minutes. Then bake in the preheated oven (electric: 200 °C/ gas: level 3) for 35-40 minutes.
Then let the cake cool down a little. Cut the cake into pieces and serve. Whipped cream tastes good with it.