The sour cream can easily be changes for something else - fx yoghurt! As go for the chocolate: just use the kind, you have lying around at home :)
Mix sour cream (2,5 dL), soft butter (170 g) and eggs (2) together...
... Until it looks something like this
Add sugar (70 g), baking powder (25 g), vanilla sugar (2 teaspoon) and salt - mix everything together
Add the first 300 g of flour - and mix
Add the last 300 g of flour and mix
Add chopped chocolate (150 g)
Mix until smooth
Make 12 buns and add them to a baking sheet
Brush with sour cream
Bake for 13 min. At 200 degrees Celsius
And then they are done! Enjoy!