Wikipedia
Krofne (, , , , ) are airy filled doughnuts. They are round and usually filled with jelly, marmalade, jam or chocolate as well as butter, nutella and cinnamon. They can also be filled with custard, or cream, but that is usually less common. The name comes from German Krapfen, and it is a variation of the Central European pastry, known as Berliner. They are also similar to the beignets.
The recipe for home-made krofne includes yeast, milk, sugar, flour, salt, butter, eggs, rum, lemon peel, marmalade and powdered sugar. The dough is kneaded and prepared and then cut into small pieces then made into a little ball, making it easier to cook and it has a nicer form.
In Croatia and Slovenia, the consumption of krofne increases significantly during the yearly winter festival of Carnival. As a good luck sign as well as for prosperity, they are served on New Year's Day. On other holidays such as Easter, Christmas and Thanksgiving these desserts are also served.