For the dough, knead the yeast, milk, sugar, flour, egg, egg yolks, 80g butter, 1 pinch of salt, vanilla pulp and lemon zest. Let rise in a warm place for about 30 minutes.
Knead the dough again and let rise again, about 15 minutes.
Then shape into 16 balls. Make a well in each ball and add 1/2 teaspoon of jam.
Preheat oven to 175 degrees.
Seal the dough over the filling with your fingers (squeeze). Place the Buchteln with the seam down in a greased, ovenproof dish. (e.g. casserole dish)
Let the Buchteln rise for another 15 minutes. Brush with melted butter, sprinkle with powdered sugar and bake at 175 degrees for 20 minutes.