Oliebollen are sold all over the country from brightly lit stalls that start to appear near markets and train stations from the end of autumn, marking the changing of the season. As well as the standard oliebollen, you can also indulge in ones with fillings such as apple, cherry, banana or custard - these are called 'berlinerbollen', and are more like a British doughnut. Another variation eaten on New Years' Eve is the 'appelbeignet' - slices of apple coated in a similar yeast-based dough and deep-fried.
All that fat is great for soaking up the alcohol. Fijne jaarwissleing!