Knead flour, butter in pieces, sugar and 1 egg to a smooth shortcrust pastry. Wrap in foil and chill for about 30 minutes. Roll out the dough on a greased, floured baking tray (32 x 39 cm). Prick several times with a fork. (If you want the base to be a little crispy, pre-bake the base now at 200 °C for about 15 minutes; I did not pre-bake it) Grate the marzipan. Beat the poppy seed, 6 eggs, grated marzipan and sour cream with the whisk of the hand mixer. Spread on the dough base and bake a little further down (if the base is pre-baked, bake on the middle shelf to the end) in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for about 45 minutes. Allow to cool completely.
Roughly chop the chocolate. Put chocolate, cream and coconut oil in a saucepan. With mild !!! Melt heat while stirring and spread on the cake. Chill for about 1 hour. Rinse knife hot and cut the cake into fine strips. Dust with cocoa and serve. (If you put the slices back in the cold in between, they are also stackable).
2 1/2 hours waiting time