Mix flour and baking powder. Add sugar, vanillin sugar, eggs, oil and 1/8 litre water and mix with the whisk of the hand mixer to a smooth dough. 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 (20 cm Ø). In a preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see
manufacturer) bake for about 1 1/4 hours. If necessary, cover with foil after approx. 45 minutes. Take the finished cake out of the oven, let it rest in the mould for about 10 minutes, remove the edge of the springform pan and bake the cake in the oven.
Stir the jelly with a whisk until smooth. Whip 75 g jelly, cream cheese and icing sugar with the whisk of the hand mixer for about 2 minutes until creamy. Whip cream until stiff and fold in. Remove the cake from the springform pan and place on a cake platter.
Spread cream loosely on top. Warm the rest of the jelly in a small pot and drizzle over the cream.