Finely grate the marzipan. Chop dark chocolate and melt over a warm water bath. Cream fat, sugar and vanillin sugar. Stir in eggs bit by bit. Mix flour with baking powder, stir in alternately with milk
Cut the dough in thirds. Stir into the one third poppy seed, into the second marzipan and into the last third chocolate coating. Grease a ring cake tin (2.5 litres capacity; 22 cm Ø) well and sprinkle with flour. First fill in the poppy seed dough, then fill in the marzipan dough and dark dough side by side. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for 55-65 minutes
Take out the cake and let it rest in the mould for about 10 minutes. Turn onto a cake rack, let it cool down
Chop the white chocolate coating and carefully melt with coconut oil over a warm water bath. Leave to cool a little. Spread the couverture over the cake. Sprinkle with poppy seeds and leave to dry
Preparation time approx. 1 3/4 hours. waiting time approx. 2 hours