Dissolve the yeast in the other half of the milk and knead with the remaining ingredients except for the egg yolk, sesame seeds and water to form a smooth and relatively soft dough. Knead the dough for at least 10 minutes (with your hand a little longer) until it no longer sticks and bubbles.
Cover and let rise for about 60 minutes. Then knead again thoroughly, let relax for 5 minutes and divide into 12 servings. Thoroughly knead each portion again and shape (grind) into balls with a high surface tension.
Whisk the egg yolks with the water. Immediately brush the tops with the whisked egg yolk and dip in a bowl of sesame seeds.
Place the dough balls on a baking sheet with enough space between them and let rise for 45 minutes, covered.
Meanwhile preheat the oven to 225 ° C. Provide steam in the oven and slide in the tray. Reduce the temperature to 200 ° C and bake for about 20 - 30 minutes.