Put the flour in a mixing bowl. Press a depression in the middle. Crumble the yeast into the hollow. Add honey and 1/8 litre lukewarm water. Mix with some flour to a liquid pre-dough and let it rise covered in a warm place for about 10 minutes.
Add sugar, fat, salt and milk. Knead into a dough with the remaining flour. Cover and allow to rise for about 30 minutes until the dough doubles in volume. For the crumbles, crumble the marzipan into a bowl.
Add fat and sugar and mix. Add flour. Knead everything into crumbles with your hands and put in a cool place. Wash, halve and stone the plums. Grease a baking tray (approx. 32 x 39 cm).
Roll out the yeast dough to the size of a baking tray on a floured work surface and place on the tray. Place plums on the dough like roof tiles. Sprinkle with vanillin sugar. Bake in the preheated oven (electric oven: 175 °C/ gas: level 2) for approx. 15 minutes.
Sprinkle crumbles on the plums. Bake the cake at the same temperature for another 15-20 minutes. Makes about 15 pieces.