Wash the potatoes thoroughly and boil for about 25 minutes. Meanwhile, for the sauce, mix sauce powder, 2 tablespoons of sugar and 6 tablespoons of milk. Bring the remaining milk to the boil, remove from the heat and stir in the sauce powder. Place back on the stove and bring to the boil while stirring. Pour the finished sauce into a bowl and stir from time to time. Drain the potatoes, rinse with cold water and peel.
Press the still hot potatoes through a potato press. Add flour, egg yolk, 10 g fat and 1 teaspoon salt and knead with the dough hooks of the hand mixer. Let the dough rest for about 15 minutes. In the meantime, pour the apricots onto a sieve, drain and place 40 halves on kitchen paper. Place 2 apricot halves filled with a piece of sugar cube on top of each other. Form the dough into a roll on a well floured work surface and cut into 20 slices of the same size. Place one slice in each floured palm and press a depression in the middle. Place a filled apricot in it, press the dough around the apricot and form into a dumpling. Cook the dumplings in portions in plenty of boiling salted water for about 10 minutes. Remove dumplings with a skimmer and drain well. Heat the remaining fat in a pan. Stir-fry breadcrumbs and the rest of the sugar until golden brown and place on a deep dish.
Place a filled apricot in it, press the dough around the apricot and form into a dumpling. Cook the dumplings in portions in plenty of boiling salted water for about 10 minutes. Remove dumplings with a skimmer and drain well. Heat the remaining fat in a pan. Stir-fry breadcrumbs and the rest of the sugar until golden brown and place on a deep dish. Roll dumplings in it and dust them thickly with icing sugar. Arrange on plates with vanilla sauce and sprinkle with pistachios. Serve decorated with lemon balm leaves and remaining apricots