Here's one of my favorites:
Melt 125 gr butter, 100gr powdered sugar and 200 gr dark chocolate. Take candy paper cups, put a cherry in each (we use cherries from '' slatko'' , a traditional thin fruit preserve but you can just boil cherries and sugar until it gets the consistency of syrup) and fill in with melted chocolate. Refrigerate.
As luck would have it, we were hoarding a couple of jars of sour cherry compote, which is not easy to get hold of in the UK, and which sounds like it's very close to the Serbian "slatko" Tatjana mentions. Looking at Google images, there are lots of ways to decorate these, we went for the messy "let's just plop them in the paper cups" approach.