This delicious cake is a twist on the classic pineapple upside-down cake. The sweet and tangy combination of strawberries and rhubarb make for a perfect topping on a moist and fluffy cake. To make this cake, start by melting butter and brown sugar in a skillet, then add sliced rhubarb and strawberries. Pour the cake batter over the fruit and bake until golden brown. Once done, flip the cake over onto a serving platter and enjoy!