August 2 is National Ice Cream Sandwich Day, and this year marks the delicious delicacy's 120th birthday. But what exactly constitutes an ice cream sandwich? In America, it’s typically ice cream flanked between two chocolate wafer-like pieces with holes punched in them, but you can use biscuits, cookies, and a number of other treats as the "bread."

In the beginning, vanilla was the standard flavor for the filling of an ice cream sandwich, but flavors evolved to include Neapolitan (chocolate, vanilla, strawberry), and nowadays every flavor under the sun. In honor of the holiday, and the 120th anniversary of the treat's invention, let's pay tribute to the iconic frozen novelty.

1. New York City street vendors started selling ice cream sandwiches in the late 1800s.

No one is sure of the exact date the ice cream sandwich was first invented, but food writer Jeri Quinzio told The Boston Globe that the earliest versions of them were called hokey pokeys and that street vendors were selling them on the Bowery in New York City at the turn of the 20th century. Back then, the humble sandwich was just ice cream held together with two pieces of paper. The cost of the frozen treat? One penny.

Quinzio cited an 1899 article in the New York Mail and Express, which stated: “There are ham sandwiches and salmon sandwiches and cheese sandwiches and several other kinds of sandwiches, but the latest is the ice-cream sandwich.”

2. The earliest known ice cream sandwich recipe used sponge cake.

According to the Food Network, the earliest known ice cream sandwich recipe wasn't made with biscuits, but two slices of sponge cake.

3. Ice cream sandwiches were developed as a cheap treat, but soon became a staple at high-end eateries.

Because the "sandwiches" were sold on the street, they catered more toward working-class individuals. However, the deliciousness of the treats quickly caught on and became a hit with Wall Street workers. On August 19, 1899 the New York Sun ran a story about the phenomenon, stating: "The brokers themselves got to buying ice cream sandwiches and eating them in a democratic fashion side by side on the sidewalk with the messengers and the office boys."

Eventually, high-end restaurants started serving them, and "Elite confectioners started using plates and forks in a dainty fashion, and saying [their sandwiches were] so much better than the ones sold on the street," Quinzio told The Boston Globe.

4. The ice cream cookie sandwich was born in San Francisco.

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Cookies have become a popular alternative to the basic chocolate wafer in building an ice cream sandwich, and we apparently have California to thank for that. According to the Food Network, in 1928, an ice cream vendor in San Francisco decided to place a glob of ice cream between a pair of oatmeal cookies then dip the whole thing in chocolate. And a whole new kind of ice cream sandwich was born.

5. A baseball stadium food vendor gets a lot of credit for inventing the modern-day ice cream sandwich, but that might be because of Wikipedia.

According to various accounts, it was Jeremy Newberg—an ice cream vendor at Pittsburgh's former Forbes Field—who supposedly created the vanilla-and-chocolate ice cream sandwich: a perfect block of vanilla ice cream gently placed between two rectangular chocolate wafers. He made and sold these ice cream treats at baseball games in the 1940s.

The Boston Globe interviewed Newberg ;(who is now 91) and his family to discuss his contributions to the ice cream sandwich world. While Newberg confirmed that he did indeed sell the desserts at the stadium for a nickel apiece, his grandson Matt was less committal. Because Newberg has long talked about his role in the treat's invention, Matt explained that "as an ode to my grandfather, I cited him as one of the inventors [on] Wikipedia." Which is how Newberg's name has become so closely associated with the dessert. "We’re not sure he’s actually the inventor," Matt admitted, "but we call him that because we love him."

6. Other countries have their own versions of the ice cream sandwich.

While the ice cream sandwich is an American invention, the treats have inspired countries like Australia, Ireland, Singapore, Israel, Uruguay, Iran, and Vietnam to concoct their own versions. In Iran, there's the bastani-e nooni, which is saffron and rosewater ice cream served between two wafers and dipped in pistachios. Vietnam street vendors sell bánh mì kẹp kem, ice cream smashed between two pieces of bread—a bona fide sandwich—and topped with crushed peanuts.