Mix 500 g flour, yeast, 75 g sugar and 1 pinch of salt. Melt 100 g butter, add milk. Add 1 egg to the flour. Knead everything with the dough hooks of the hand mixer to a smooth dough. Cover and leave to rise in a warm place for about 30 minutes. Grease a fat pan (approx. 32 x 39 cm) and dust with flour.
Wash the plums, remove the stalks, halve and stone them. For the icing, mix pudding powder, 50 g sugar, sour cream and 3 eggs. For the crumbles, mix 300 flour, 125 g sugar, vanillin sugar, baking powder and 1 pinch of salt. Add 1 egg and 175 g butter in pieces. Mix everything first with the dough hooks of the hand mixer, then quickly with your hands to make crumbles. Roll out the yeast dough on the fat pan and press it up at the edge. Cover and leave to rise for another 15 minutes. Place the plums close together on the dough. Pour over the top with a sand glaze. Sprinkle with crumbles. Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for 40-45 minutes. Leave to cool for about 2 hours.
Cover and leave to rise for another 15 minutes. Place the plums close together on the dough. Pour over the top with a sand glaze. Sprinkle with crumbles. Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for 40-45 minutes. Leave to cool for about 2 hours. Sprinkle with sugar and decorate with mint. Whipped cream tastes good with it