This beautiful cake is perfect for a special occasion. The strawberries and rhubarb are caramelized on the bottom of the pan, and then the cake batter is poured on top. When the cake is flipped over, the fruit is on top and the cake is moist and delicious. Using a food processor to mix the batter makes it easy to prepare. Serve it with whipped cream or ice cream for a decadent dessert.