This orange pineapple upside-down cake recipe is perfect for those who enjoy a citrusy and sweet combination. The cake batter is made with flour, sugar, baking powder, salt, butter, eggs, milk, and orange zest in the food processor. The pineapple topping is made the same way as the classic recipe. The cake is baked until golden brown and served warm. It's a delicious and refreshing dessert that's perfect for any time of year.