Answer: Peanut Butter
In the 2000s, for a brief and curious time, you could acquire a culinary curiosity that has never been seen before (and has not been seen outside of very limited markets in Hawaii and Arizona ever since) : packaged peanut butter slices.
The product was developed by Stewart Kennedy, a former business and marketing specialist in the agri-food industry. He passed the idea on to a food engineer and in turn gave it to the Oklahoma Peanut Commission (peanuts are a serious business in Oklahoma). After burning hundreds of pounds of peanut butter and a large number of flawed formulations, they made a slice of peanut butter that was shelf-stable, wrapped in plastic, and came out clean when making a sandwich. 1