An upside-down cake is a cake usually made in a pan with a curved bottom then, once cooked, turned over and allowed to set, and is eaten upside-down. Usually, chopped fruits such as pineapples and cherries are placed at the bottom of the pan before the batter is poured in, so that they form a decorative topping once the cake is inverted.

In culture
Pineapple Upside-down cake is referenced in

the Brak song "I Like Hubcaps" from the album: Brak Presents the Brak Album Starring Brak. In the song, Brak says: "I like pineapple upside-down cake, why's it upside-down? WHY'S IT UPSIDE-DOWN?"

In the first episode of The Jetsons (Rosey the Robot, Sept. 23, 1962), Rosey clobbers Mr. Spacely with a pineapple upside-down cake after he makes an insulting comment. Spacely then fires George, but later calls from a pay phone and offers him his job back after tasting the cake - which he is still wearing on his head.