Hey there!
Im from Germany, so I know what youre speaking of.

Mmm, I luv Quarkstuten! Its such a lovely bread! There are basically two ways you can make this sweet bread: either a yeast variation or one using a quark-oil-dough. I have translated two recipes for you, one for each variation. Ive not tried those recipes myself, but several other people have had good results with them.
1. yeast based dough:
20 g fresh yeast
4 Tbs warm water
350 g flour (a little over 2 3/4 cup)
200 g quark (13 1/4 tbs)
1/2 cup sugar (more or less depending on how sweet you want your bread to be)
50 g butter, softened (3 1/2 tbs)
2 eggs
1/4 ts salt
Directions:
Dissolve yeast in warm water.
Combine flour, butter, quark, sugar, salt and eggs. Mix in yeast.
Knead until dough is smooth and shiny.
Fill dough into a well greased loaf tin and place in oven on middle rack (do not preheat the oven!). Let rise for about 20 minutes (or until dough has doubled in size) at 122F.
Then place bread on lowest rack and turn oven up to 392F (~400F). Bake for 30-35 minutes or until golden brown and cooked thourgh (you may have to cover with foil to prevent excessive browning).
2. Quark-oil-dough:
500g/ 4 cups flour
5 tbs oil
1 cup quark
1 egg
3/4 cup sugar (more or less depending on how sweet you like your bread)
6 ts baking powder
milk (only a very little bit to make the dough workable)
raisins (optional)
Directions:
Give all ingredients into a big bowl and mix until a soft dough has formed.
Fill into a loaf tin and bake at 375F in the preheated oven (second lowest rack) for about 45 minutes.
Well, I hope this helps! Good luck with the recipe and please let us know how your Quarkstuten turned out!
Best
Laura