The 19th-Century Reason Pizza Is Sometimes Called Pie
Pie is pie and pizza is pizza and the two have very little in common other than that they both have a crust of some sort and are often round and thus can be cut into wedge-shaped slices. Why, then, do pizzerias keep trying to horn in on Pi Day (not that we're reluctant to take them up on any $3.14 Pi Day deals they may have) as well as calling themselves punny names such as Pie Five and Pie High? You may have heard the term "pizza pie" bandied about from time to time, but what does this even mean? Pizza baked inside a pie crust? While that does sound weirdly delicious, "pizza pie" actually just refers to plain old pizza.
As to how this name came to be, its use dates back to the turn of the 20th century when it was an Americanization of the dish that 19th-century Italian immigrants called pizza. A 1903 New York Tribune article translates "pomidore pizza" as "tomato pie" and explains it to non-Italian readers as being pie-like based on the fact that it consists of a crust topped with tomatoes and red pepper. Another type, "salami pizza," is translated as "bologna pie," although the description sounds far more appetizing than the name: dough with tomatoes, cheese, red pepper, and bologna (perhaps it was really salami). The term "pizza pie" wasn't coined at the time, but seems to have become popular after featuring in the lyrics of Dean Martin's 1953 "That's Amore."
Tomato pie still exists in several different forms
Today pizza is known and loved all over the U.S., whether or not we're appending "pie" to its name. Tomato pie, on the other hand, is more of a regional delicacy and is one that may differ depending on where you're eating it. The tomato pies of Philadelphia are more or less Sicilian in origin, rectangular in shape, and have a crust that closely resembles focaccia. The topping is nothing more than tomato sauce with perhaps just a dusting of grated Parmesan or Romano. In Trenton, New Jersey, though, a tomato pie is more of a thin-crusted upside-down pizza complete with a layer of mozzarella cheese hidden under a sauce made of crushed tomatoes.
Down in South Carolina, however, when you order tomato pie, you're going to get an actual pie that in no way, shape, or form (other than generic roundness or wedge) resembles any kind of pizza. The filling is made from sliced tomatoes (fresh, not canned) mixed with herbs, onions, and a blend of mayonnaise and shredded cheddar or another cheese. While this type of tomato pie does sound interesting, it may be descended from an earlier version that's even further from the tomato pies of Yankeeland: a sweet dessert consisting of a crust filled with sugar-sweetened tomatoes seasoned with cinnamon and nutmeg.