Hello Dolly Bars got its name from the 1964 Broadway musical, Hello, Dolly!. The main character in the musical is named Dolly Levi, and she is known for her love of food. In one scene, she even sings a song called “Put On Your Sunday Clothes” which mentions several different desserts, including Hello Dolly Bars. It’s thought that the musical’s popularity helped to make the dessert well-known.