per Grok:
The song "I Am a Pizza" (also listed as "I Am a Pizza (The Pizza Man)" or similar variations, with lyrics including "I am a pizza, ready to eat/go") featured in the 1986 movie The Money Pit was written and performed by Peter Alsop.
It plays in the background during a scene involving a pizza delivery/truck (often recalled in clips where Tom Hanks' character reacts to the rundown house, with kids singing along). Multiple sources, including the film's IMDb soundtrack listing, fan-compiled soundtracks, and bootleg releases of the movie's music, credit Peter Alsop for writing and performing it. The track comes from his 1983 album Wha'D'Ya Wanna Do?.
(Note: There's a popular children's version/cover by Charlotte Diamond from 1985 that uses the same song and lyrics, but the original in the movie is Alsop's recording.)
This tune has become a memorable (and sometimes ironically discussed) earworm from the film!