Mix flour and baking powder. Add 250 g sugar, vanillin sugar, eggs, oil and 1/8 litre water and mix to a smooth dough with the whisk of the hand mixer. Halve the dough and stir in one half of the cocoa
Place the dough alternately with a tablespoon always in the middle (in the same place) in a greased springform pan (28 cm Ø). Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for approx. 40 minutes. Take the finished cake out of the oven, let it rest in the pan for about 10 minutes, remove the edge of the springform pan and let it cool down completely
For the lemon cream, soak gelatine in cold water. Wash lemon hot, grate dry, grate peel thinly, halve fruit and squeeze juice. Pour the apricots into a sieve and drain well
Whip the cream until stiff, pour in 60 g sugar. Squeeze the gelatine, dissolve lukewarm. Stir 2 tbsp lemon juice into the gelatine. Stir the mixed gelatine and lemon zest into the rest of the juice. Add to the cream and fold in
Cut the cake in half horizontally. Place a cake ring or the springform pan rim around the bottom cake base. Spread 1/4 of the cream on the base. Cover with apricot halves. Add the rest of the cream and smooth it down. Put the upper half of the cake on the cream and chill the cake for at least 4 hours
Bring the jam to the boil, pass through a sieve. Remove the cake from the tin and spread with jam all around. Chop the pistachios and sprinkle on the cake
waiting time approx. 2 hours