What is is your muffin buttered song?

"I Can't Believe It's Not Butter" is a commercial jingle for a margarine brand. The song is known for its catchy melody and repetitive lyrics, "Is your muffin buttered?" The jingle was created in 1980 by the advertising agency McCann Erickson and was first aired in the United States. The song was popularized by a series of television commercials that featured celebrities such as Fabio and Kelly LeBrock. Despite being a commercial jingle, the song has become a memorable pop culture phenomenon and has been referenced in various forms of media.