Cotton candy is a consumable mentioned in the Fallout 3 add-on Point Lookout and in Fallout 76.
Background
A product sold at fairs before the Great War.
Gameplay
Advertised on grandstands, cotton candy was sold alongside hotdogs, lemonade, Nuka pops, apples, and popcorn at events held at the Tyler County Fairgrounds. Cotton candy was also sold on the Pilgrim's Landing boardwalk. A pre-War bite size cotton candy product can be found throughout Appalachia.