June 22, 1847 has been somewhat arbitrarily selected as the invention date of the doughnut. According to widely accepted doughnut lore, Dutch immigrants made olykoecks (oily cakes) by frying leftover bits of bread dough in oil. Often these cakes might be twisted into knots ("dough knots"). Or, since the dough tended to remain uncooked in the middle, nuts were sometimes added to the center ("dough nuts").
The uncooked centers seem to provide the inspiration for the hole. Legend has it that New England sea captain Mason Crockett Gregory originated the doughnut hole. He always took a batch of his mother's olykoecken with him when he went to sea. In some versions of the story, he poked the nuts out of the undercooked centers because he didn't care for them. Other versions say he encountered cakes with holes in them during his journeys. (In Germanic countries, cookies and cakes with holes in them were common. They were known as "jumbles," a word developed from a two-finger ring called a gimbel.)
The most colorful story has it that Captain Gregory needed a place to put his olykoeck while he steered, and impaled it on one of the spokes of the ship's wheel. Whatever the reason for adding the hole, it made the doughnut cook more evenly and the confection soon caught on