National Jelly-Filled Doughnut Day is observed in the USA every June 8, celebrating one of America's favorite treats. The holiday honors jelly-filled doughnuts, which originated from the Netherlands, where they were first made as a sweet, fried treat called olykoek, meaning oily cake. The term "doughnut" was first recorded in 1809, but it wasn't until 1900 that the word became widely used. The iconic hole in the center of doughnuts was introduced in 1847 by Hanson Gregory, who used a tin container to punch holes, allowing for even cooking. Unlike traditional doughnuts, jelly-filled varieties do not have a hole, as they require filling to be placed inside before frying. To celebrate, people are encouraged to make their own jelly-filled doughnuts using their favorite jelly.