For the baked doughnuts, mix flour, sugar and yeast well. Add milk and knead. Add egg yolk and butter and knead into a smooth dough. Then cover and let rise in a warm place for 45 minutes.
Best in the oven at 50 degrees. Then form about 9 balls and let rise again for 45 minutes! Preheat the oven to 180 degrees (hot air) and bake for about 12 minutes.
While still warm, fill with apricot jam or Nutella.