• Preheat oven 350°F.

For the Topping

• In a small bowl, melt butter and mix in brown sugar. Spoon mixture into 1 round 8" or 9" cake pan.
• Lay out pineapple rings on top of sauce (saving the pineapple juice for the cake).

For the Cake

• In a large bowl, combine cake mix, butter, banana, vanilla extract and pineapple juice. Using an electric mixer, mix on low speed for 30 seconds, then on medium speed for 2 minutes. Pour mixture into pan over the pineapple rings and sugar mixture.
• Bake 40-45 minutes on center rack, until toothpick inserted in center comes out clean.
• Allow to cool 10 minutes in pan. Run a knife around outer edge, then invert onto serving dish or cake plate. If the cake does not want to come out, allow to cool another 10 minutes and using a spoon tap on the bottom of the pan until it comes out easily.