The Dutch pastry regarded as a predecessor of the doughnut is the oliebol.
An oliebol is a round ball of yeast-raised dough dropped into hot oil and deep-fried. The name literally means “oil ball.” Oliebollen are traditionally served in the Netherlands and Belgium around New Year’s Eve, often dusted with powdered sugar and made with raisins, currants, apple, or candied citrus.
The pastry belongs to a wider family of European fried dough foods. Its older Dutch name, oliekoek, means “oil cake,” and recipes for oliekoecken appeared in Dutch cookbooks by the 17th century. Dutch settlers carried related fried-dough traditions to North America, where they contributed to the development of American doughnuts.
An oliebol is not the same as a modern ring doughnut: it is usually spherical and has no hole. That distinction is important because early doughnuts were also commonly made as solid balls. The familiar ring shape emerged later, partly because removing the center helped thick dough cook through without leaving a raw middle.