An upside-down cake is a cake that is baked "upside-down" in a single pan, with its toppings at the bottom of the pan. when removed from the oven, the finished upside-down preparation is flipped over and de-panned onto a serving plate, thus "righting" it, and serving it right-side up. usually chopped or sliced fruits — such as apples, cherries, peaches, or pineapples — butter, and sugar are placed on the bottom of the pan before the batter is poured in, so that they form a baked-on topping after the cake is inverted. a simple cottage pudding cake batter may be used.traditional upside-down preparations include the american pineapple upside-down cake, the french tarte tatin, and the brazili...

Source: Wikipedia