Heat the milk with the butter on the stove or in the Microwave until lukewarm .
Mix the flour with sugar, vanilla sugar, yeast, and salt in a large bowl.
Add the egg and the milk, mix and knead well for about 5 minutes.
Cover the bowl and place it where it is warm. Let stand there at least 40 minutes to 1 hour.
When the dough has clearly risen and about doubled it’s volume, remove it from the bowl and start kneading it with your hands on the kitchen counter top.
Form a thick roll and cut this roll in 8 pieces about the same size.
Mold each piece of dough into a sphere.
Flatten each sphere. Make a thump depression in the center of each.
Take about one teaspoon of your preferred preserve or Jam and fill it in the depression that your thump left in the dough
Take the rims of the dough and close the depression.
In a large pot (must have a good closing lid!) put the 0.42 cups milk and 0.42 cups cream, add the butter and heat the stove on medium.
When the butter melts, sprinkle one tbsp sugar all over the milk.
Place the dough spheres into the pot with the seam placed downside and let rest for another 15 to 20 minutes.
Now close the lid.
On medium heat simmer for about 20 -25 minutes and don't open the lid. Really. I mean it. Keep it closed! But at the same time make sure your dumplings don't burn.
In the meantime, you can cook the vanilla sauce.