Line a baking tray (approx. 35 x 40 cm) with baking paper. Separate the eggs. Beat the egg whites and 1 pinch of salt until stiff, sprinkle 75 g sugar and vanillin sugar. Fold in the egg yolks one by one. Sift flour, starch and baking powder on top and fold in
Spread the sponge cake on the tin. Bake in the preheated oven (electric cooker: 200 °C/circulating air: 175 °C/gas: level 3) for 10-12 minutes. Turn out onto a damp tea towel. Peel off baking paper. Let the sponge cake cool down
Defrost and drain the raspberries. Soak gelatine in cold water. Cut out a plate (approx. 25 x 32 cm) from the sponge cake and place it on a tray. Place a rail made of multiple folded aluminium foil (approx. 6 cm wide) or a square baking frame around it
Whip the cream until stiff. Mix yoghurt, 150 g sugar and lemon peel. Squeeze the gelatine and dissolve at low heat. First stir in 3 tbsp. yoghurt cream, then stir into the rest of the cream. Fold in cream and 400 g raspberries. Spread on the sponge cake. Spread the rest of the raspberries on top. Crumble the rest of the sponge cake, sprinkle on the top and press down lightly. Put it in a cool place overnight. Dust with icing sugar just before serving