I was recently in Shanghai and we spotted (at several locations) vendors selling a snack my wife, a Shanghai native, was unfamiliar with. It was balls of fried dough (cooked in a mold) filled with nothing but air, and drizzled with what looked and tasted like tartar sauce. They seemed to be all the rage with school-aged girls in particular, but we found them disappointingly insubstantial ("fried air" my wife called them).
There's a picture of them linked below. Does anyone know what they are called or where/how they originated?