Wiktionary
n. 1 (misspelling of huckaback English) 2 A frozen dessert popular in Louisiana, consisting of a frozen sweet drink usually served in a paper cup.
Wikipedia
A huckabuck, also known as a hucklebuck, is a homemade frozen dessert enjoyed by people in Louisiana and Georgia, particularly New Orleans and Macon. It consists of a paper cup that is filled with some sort of sweet liquid like Kool-Aid, and frozen. Children buy them on their way home from school for a dime, or sometimes a quarter; other things are generally sold with them: pickles or candy are favored. The trick to eating it is to flip the huckabuck over so the soft sugary part is at the top. Then grab a plastic spoon and dig in. They are still served to this day at the New Orleans Jazz Festival, in many neighborhoods around central and southern Louisiana.