Put the flour in a bowl and press a depression in the middle. Warm 100 ml milk lukewarm. Add yeast and 25 g sugar to the milk and mix well. Pour milk into the flour bowl, mix with some flour and cover with flour. Cover and leave to rise in a warm place for about 15 minutes. Melt butter.
Mix 50 g sugar, egg, liquid butter and 150 ml milk and add to the flour. Use the dough hooks of the hand mixer to make a smooth dough, if necessary knead with your hands at the end. Cover the dough and let it rise again in a warm place for about 20 minutes. Wash, stone and fourth plums. Wash apples, quarter and core them. Cut quarters into 3 slices. Roll out the dough on a floured work surface (approx. 32 x 39 cm) and place on a greased baking tray sprinkled with flour. Cover the cake with rows of apples and plums. Sprinkle apples with 1 tablespoon of sugar. Bake the cake in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for approx. 30 minutes. Beat the egg whites until stiff, sprinkle with 150 g sugar. Pour meringue mixture into a piping bag with a star-shaped spout.
Roll out the dough on a floured work surface (approx. 32 x 39 cm) and place on a greased baking tray sprinkled with flour. Cover the cake with rows of apples and plums. Sprinkle apples with 1 tablespoon of sugar. Bake the cake in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for approx. 30 minutes. Beat the egg whites until stiff, sprinkle with 150 g sugar. Pour meringue mixture into a piping bag with a star-shaped spout. After 10 minutes, take the cake out of the oven, squirt the meringue between the rows of fruit and sprinkle the plums with 1 tablespoon of sugar. Bake for another 20 minutes, then remove the cake from the oven and let it cool down.