Mix sugar, salt, vanilla, quark, oil and milk well and then mix flour with baking powder and knead in. Finally knead in the chocolate.
Roll out the dough into a rectangle on a floured work surface. Divide this into 6 rectangles and cut them in half diagonally. So you get 12 triangles, which you roll up from the short side to small croissants and spread on one or two baking sheets lined with baking paper. Now you should brush them with a little milk or egg / yolk / egg white to make them look nicer.
Bake for 20 minutes at 200 ° C top / bottom heat.
The croissants taste delicious even after half a day and are also a good afternoon snack.