Defrost raspberries at room temperature. Wash 2 lemons hot, rub dry. Grate the skin thinly, halve the fruit and squeeze the juice. Pass the raspberries through a sieve. Separate eggs
Mix flour, starch and baking powder. Whisk the egg yolks, 250 g sugar and vanillin sugar with the whisk of the hand mixer until creamy white. Alternately add flour mixture, oil and 2 tbsp. lemon juice and stir in. Halve the dough. Stir the raspberry puree into 1 half and 4 tbsp lemon juice and half lemon zest into the other half. Beat the egg white until stiff, halve it and fold one half into the dough halves
Grease a springform pan (24 cm Ø) and sprinkle with flour. Pour in the dough alternately by the spoonful and smooth it down. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for about 1 hour. Let it rest in the pan for 10 minutes, then carefully loosen the edge of the springform pan and let it cool down
Soak gelatine in cold water. Mix yoghurt, 2 tablespoons lemon juice and 80 g sugar. Dissolve the gelatine in warm water. Add 2 tbsp. cream to the gelatine and stir until smooth. Pour the mixed gelatine into the cream and stir in quickly. Chill the cream for about 30 minutes. Whip cream until stiff and fold into the cream. Cut the cake in half horizontally and place a cake ring around the bottom half. Spread the cream on the base and smooth it down. Carefully place the upper cake layer on top of the cream and refrigerate the cake for about 4 hours
Wash the rest of the lemon thoroughly and cut into thin slices. Bring 1 tbsp. sugar and 1 tbsp. water to the boil in a large pan. Caramelise the lemon slices for about 1 minute while turning. Mix the rest of the lemon peel and 1 tbsp. sugar. Remove the cake from the cake ring. Spread lemon sugar around the edge. Cover cake with lemon slices
waiting time approx. 4 hours