How about a redo? I mean... "Do you wanna a bite?" isn't exactly correct. There is no need for the "a" after "wanna". I get that dictionaries usually define 'wanna' as 'want to', but it generally accepted as also referring to 'want a'.
So "Do you wanna a bite?" = "Do you want to a bite?" or "Do you want a a bite?", are all incorrect.
Either "Do you want a bite?" or "Do you wanna bite?".