Mix flour, sugar and salt. Heat milk and fat. Dissolve yeast and add to the flour. Knead to a smooth dough with the dough hooks of the hand mixer. Cover and leave to rise in a warm place for about 30 minutes.
In the meantime, wash, halve and stone the plums. Knead the dough again and roll out on a baking tray (42 x 37 cm) lined with baking paper. Spread the plums on top and press them lightly into the dough.
Let it go for another 30 minutes. Bake in the preheated oven (electric cooker: 200 °C/level 3) for 35-40 minutes. Allow to cool and sprinkle with sugar crystals. Results in about 20 pieces.