We were in the Wonderopolis kitchen making breakfast the other day when we overheard the toast and the cereal telling jokes:

Toast: Hey cereal! Why did the donut have to go to the dentist?

Cereal: I have no idea. Why?

Toast: Because it needed a chocolate filling!

Cereal: Ay yi yi. You must have forgotten your butter, because that was really dry!

OK…so breakfast food humor might not be all it's cracked up to be. But we bet you wouldn't mind a donut, would you, especially if it had chocolate filling?

Donuts — sometimes spelled doughnuts — are tasty treats made from fried dough. They come in a wide variety of shapes, sizes, and flavors. Do you have a favorite type of donut?

Probably the most popular and familiar type of donut is the classic ring-shaped donut with a hole in the middle. Although these basic donuts can come in many different flavors with all sorts of different toppings, the most common type features a basic sugar glaze coating.

Many children are fascinated by the hole in the middle of the donut. Why is it there? What purpose does it serve?

There are a couple of common theories about the origin of the donut's hole. One of the most popular credits American seafarer Hanson Gregory with inventing the donut's hole in 1847 while aboard a lime-trading ship. He was just 16 years old at the time.

As the story goes, Gregory wasn't happy with the doughy consistency of the fried cakes served on the ship. Although the outsides and the edges were crisp, the centers of the donuts were always greasy and doughy.

Gregory suggested punching a hole in the middle of the fried cakes, so that the insides of the cakes would cook as evenly as the outsides. Experts believe that this reason makes sense, because of the way that donuts are cooked.

When dough is placed in a fryer, the outsides and edges will cook quickly, because they're exposed to the hot oil. To fully cook the insides of the dough, the dough would have to stay in the oil for a longer time, which would lead to the outsides becoming burnt.

Punching a hole in the middle of the dough, however, allows the insides and the outsides to cook evenly, creating a perfect donut. There may be another reason for the holes in donuts, though.

Donuts became popular in America around the same time bagels were becoming popular. Bakers and street vendors would often sell bagels stacked on long sticks or strung on a long rope. Some people believe that the holes in donuts allowed them to be sold in a similar way.

So what happens to all those donut holes that are cut out of the dough? Many people believe that those pieces of cut-out dough are what are used to make donut holes, which are those little round donut pieces that so many kids love to eat with milk.

In truth, though, many donuts with holes don't actually have any dough cut out of them to make their shape. Instead, special machines spray dough into a fryer in a circular pattern. The donut holes you buy at the bakery or grocery store are usually made out of dough simply cut into small squares!