Stir yeast with 1 tablespoon of sugar until liquid. Melt fat, add milk. Mix flour, 1 pinch of salt and 75 g sugar.
Add yeast, lukewarm milk-fat mixture and egg to the flour and knead all ingredients into a smooth dough. Cover and leave to rise in a warm place for about 30 minutes.
Wash, halve and stone the plums. Knead the yeast dough well again. Grease the oven pan 32 x 38 cm and roll out the dough in it. Mix nuts, cinnamon and 4 tablespoons of sugar and sprinkle evenly on the dough. Spread plums on the dough with the open side facing upwards. Bake in the preheated oven electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2; approx. 30 minutes.
Take the finished cake out of the oven, sprinkle with sugar crystals and let it cool down. Cut the cake into pieces and serve. Whipped cream tastes good with it.