Wash and clean the strawberries. Sort and wash blueberries. Cream fat, lemon zest, 400 g sugar, vanillin sugar and salt with the whisks of the hand mixer. Stir in the eggs one after the other. Mix flour and baking powder, stir in. Grease a fat pan of the oven (approx. 32 x 39 cm) and dust with flour. Add the dough and smooth it down
Spread the fruit evenly on the dough. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) on the lower rack for approx. 45 minutes. Take out and let cool down. Beat the egg whites until stiff, adding 250 g sugar. Spread the beaten egg whites loosely on the cake with a tablespoon and bake in a preheated oven (electric range: 225 °C/ convection oven: 200 °C/ gas: see manufacturer) for approx. 8 minutes. Take out, let cool and cut into pieces
Waiting time approx. 1 hour