First heat the milk with butter. Knead with the remaining ingredients to a smooth yeast dough.
Let dough rise at room temperature until doubled in volume.
Knead the dough again by hand. Cut off pieces, add 1 tablespoon of Powidl to each piece and roll into a ball. Place in a greased baking dish and let rise again briefly.
Brush with butter. Bake at 180 °C top/bottom heat for approx. 30 minutes.
For the vanilla sauce, heat milk, stir 3 tablespoons milk with vanilla pudding powder and powdered sugar until smooth.
Stir the vanilla pudding into the warm milk and simmer gently for about 5 minutes.
Serve the booklets with the vanilla sauce.