A candy bar is a type of snack, sometimes coated with chocolate.
While at the Starfleet Medical Academy, Julian Bashir designed a candy bar that he believed had "far superior" nutritional values to Starfleet rations. (DS9: "The Siege")
In 2024, Bashir tried to get a candy bar for Lee, a woman who suffered from hypoglycemia. (DS9: "Past Tense, Part II")