You might be wondering what a pair of pants and a pizza has to do with calzone.

Calzones, or Calzoni (plural in Italian), are a form of folded pizza. While pizza first started to become popular in the 19th century Naples, the round, flat bread that we think of today as Neapolitan pizza wasn’t the only form. Not only were some pizza fried (pizza fritte), but some pizza was stuffed.

Calzoni were originally made from two long sheets of dough layered together over the stuffing. These stuffed tubes were said to look like the legs of a pair of trousers. You might see where this is going: Calzoni also means trousers or pants in Italian, and so the term was applied to the delicious filled bread.

Today, a more common shape is crescent or half circle formed from taking a round piece of dough and folding over itself. With this folded circle of dough the connection to pizza is more evident. Calzones are literally folded pizza.

Calzones became a popular Italian American dish in the 20th century. They were introduced to a wider audience through Italian festivals like New York’s feast of San Gennaro. As early as the 1920s, calzones were sold from stands along the festival route.

As pizzerias became a popular “fast food,” calzone were added to the menu of local pizza parlors.

The most common fillings include cheese and ham or other cured pork. But calzones are versatile and can take on the same fillings as would top a pizza. Particularly wet ingredients can cause a challenge for calzone, and this is why sauce is rarely added to the filling. Instead, sweet marinara is usually served alongside a calzone, or sauce is spooned over the baked dish.

While Calzone are a form of stuffed pizza, they shouldn’t be confused with a similar stuffed food, the Stromboli. A stromboli is more like a sandwich, with dough rolled around fillings before being baked. Calzones do not have layers of dough in the middle, as can happen with a rolled bread like stromboli.

The stromboli is an American original, invented in Philadelphia around 1950 by Nazzareno “Nat” Romano. The rolled up dough usually is longer rather than rounder, and usually is packed with good melting cheese like mozzarella and meats.

Philadelphia might be known for cheesesteaks, but really the stromboli are what you should be eating. Eater has a list of some of the best.

Stromboli spread outward from Philadelphia across in the mid-Atlantic. In 1977, Stuff Yer Face opened in New Brunswick, New Jersey serving up a variety of “boli,” the restaurant’s shorthand for stromboli, significant only because celebrity chef Mario Batali got his start cooking in the kitchen there.

Another name for this kind of stromboli is Pepperoni Bread, with the fillings being pepperoni slices and provolone cheese generally available along the east coast of the United States.

In the 1920s, West Virginia coal miners ate a similar bread known as a Pepperoni Roll. These are more bread-like, stuffed with pepperoni and cheese like mozzarella or pepper jack. They were officially invented by Giuseppe “Joseph” Argiro in 1927 and were often baked by miner’s wives. It has since become the official state bread of West Virginia.

Another type of “stromboli” made of meats on French Bread was invented on the west coast a few years after the Stromboli were invented in Philadelphia. Mike Aquino invented the sandwich for Mike’s Burger Royal and started serving it in 1954. The shop has recently closed.

But back to Calzone. The best calzone will be made with straight up pizza dough so that the outside is crispy and interior slightly chewy, like a New York slice. Calzone can be deep fried, but a skilled baker (and especially hot oven) will create a similar effect.

Calzone are often featured at street fairs or at boardwalk stands along the Jersey shore, but as Neapolitan-style pizza has grown in popularity, a new wave of high-end, customized calzone have cropped up on menus. GrubStreet put together a list of the best calzone in New York City (back in 2017).

For me the best Calzone still probably comes from Helen’s Pizza in Jersey City. This is truly a highlight of the genre filled with mozzarella and ricotta cheese and stuffed with whatever meat you prefer. I like it filled with pieces of fried chicken cutlet, but bacon or ham is good too.