Why is it called pancake fruit?

Pancakes are Tianjin snacks. It consists of mung bean pancakes, eggs, fried dough sticks or crispy "chicken gizzards", with flour paste, chopped green onion and Chili sauce (optional) as seasoning, which tastes salty and fragrant. At present, the raw materials of pancake crust are not only limited to pancakes spread out from mung bean noodles, but also a variety of choices such as soybeans and black bean noodles. However, Tianjin people still adhere to the traditional way of eating. The only ingredients used in authentic pancake fruit are mung bean noodles, fried dough sticks, chopped green onion, sesame seeds and other condiments. Many provinces outside Tianjin have raw materials such as ham, sausage, even shredded bean curd and shredded meat floss in their pancakes. Although they are named pancake fruit by merchants, they are all in name only, far from authentic.