Preheat oven to 375°.
Pour melted butter into a 9 x 9 inch baking dish.
Top with brown sugar.
Drain pineapple, reserving the juice.
Layer 9 pineapple rings over brown sugar and set aside.
In a mixer bowl, beat the egg whites until stiff peaks form, set aside.
In another bowl, combine egg yolks with sugar, vanilla and 1/3 cup reserved pineapple juice using a whisk or wooden spoon.
Add flour, baking powder and salt.
Stir just until combined.
Fold in whipped egg whites.
Pour over pineapple and smooth evenly.
Bake for 30- 35 minutes or until a toothpick inserted near the center comes out clean.
Remove from oven and set on a wire rack to cool 10 minutes.
Drain cherries on a paper towel to remove excess juice and set aside.
Invert onto a serving plate by laying the plate over the cake pan and then flipping it over.
Place a cherry into the center of each pineapple ring.
Serve warm or at room temperature.