According to Wikipedia: "A fluffernutter is a sandwich made with peanut butter and marshmallow creme. Its name comes from the common use of "Marshmallow Fluff" brand marshmallow creme. It is particularly popular in the Northeastern United States states and has been proposed as the official Massachusetts state sandwich."
"Variations of this recipe include the addition of bananas, honey, graham crackers, M&M's, or any ingredients that are deemed compatible with peanut butter. The traditional method of combining the peanut butter and marshmallow creme is simply spreading one slice of bread with each and combining them into a sandwich; however, some purists contend that mixing equal amounts of both in a bowl and spreading them together results in a superior texture and taste. This particular method of preparation, however, has never appeared in the manufacturer's official cookbooks and is contrary to the popular commercial jingle which advises purchasers on the proper way to construct a Fluffernutter.
In June 2006, Massachusetts State Senator Jarrett Barrios gained national attention when he proposed legislation restricting the serving of Fluffernutter sandwiches in public schools. The proposal was widely mocked as an example of trivial and overly intrusive legislation, while Barrios supporters pointed to concerns over the problem of childhood obesity.
"Fluffernutter" is a registered trademark of Durkee-Mower Inc., the maker of "Marshmallow Fluff" brand marshmallow creme. However, Durkee-Mower's US trademark registrations for Fluffernutter cover only ice cream and printed recipes. In 2006, Durkee-Mower sued Williams-Sonoma Inc. in the United States District Court for the District of Massachusetts, alleging that Williams-Sonoma was selling a marshmallow and peanut butter chocolate-covered candy under the "Fluffernutter" name.