Mix in half of the flour, sprinkle more flour on top, cover, and let rise in a warm spot for about 30 minutes.
Beat the rest of the flour, the salt, egg, sugar, and oil into the starter dough with a cooking spoon until the dough comes away from the side of the bowl.
Cover and let rise another 20 minutes.
Roll out to ½ in (1 cm) and cut out circles with a 2½ in (6 cm) cookie cutter.
Mix the apricot marmalade with rum and spoon onto each circle.
Bring the edges together, and dip them in butter.
Place the buchteln with the edges down in a buttered pan.
Preheat oven to 350 °F (180 °C).
Let the buchteln rise for another 20 minutes.
Brush with melted butter and bake for about 30 minutes.
In the meantime, prepare the vanilla sauce.
Dust the buchteln with confectioner’s sugar before serving with the warm vanilla sauce.
