Mix the cocoa, vanilla sugar, oats and cocoa in a large bowl until well combined.
In a separate bowl, stir the coffee and quark until combined and then add to the dry ingredients. At this point you might want to refrigerate for about an hour, just so the mixture hardens and is a little easier to handle.
Place coconut or pearl sugar on a large plate. Scoop out around one tablespoon-sized amounts of dough and shape into balls. Roll in the coconut or pearl sugar and place on a baking tray lined with grease-poof paper. Put in the fridge until ready to be eaten. Enjoy!