Upside-Down cakes originated in North America, and were (and sometimes still are) baked in cast iron frying pans. The most popular flavor is Pineapple.
Double Pineapple Upside-Down Cake
Here is a recipe for a Double Pineapple Upside-Down Cake which has pineapple in and on the cake.
German Chocolate Upside Down Cake
Here is a recipe for German Chocolate Upside-Down Cake.
Mini Pineapple Upside-Down Cakes
Here is a recipe for mini pineapple upside-down cakes.
Pineapple Rum Upside Down Cake
This Pineapple Rum Upside Down Cake is a family favorite.
Rhubarb Upside Down Cake
Here is a recipe for Rhubarb Upside-Down Cake, which is made with fresh or frozen rhubarb.
Upside-Down Apple Cake
Here is an apple recipe for Upside-Down Apple Cake.
Pear Gingerbread Upside-Down Cake
Here is a recipe for Pear Gingerbread Upside Down Cake.
Double Upside Down Cake
Here is recipe for Double Banana Upside Down Cake.
Rhubarb is a vegetable that is eaten cooked along with sugar. Here are several recipes.
Pineapple Upside-Down Cake
Here is one of my favorite recipes for Pineapple Upside-Down Cake.