Position a rack in the center of the oven and preheat the oven to 350 degrees F.
Add butter to a 9-inch round baking pan and place inside of a warm oven until melted (about 5 mins).
Remove from oven and sprinkle brown sugar evenly over the butter. Add 6 pineapple slices and place a cherry inside of each one. Fill in the nooks and crannies with whole pecans (optional).
In a medium bowl, combine the sifted flour, baking powder and salt...and stir.
Using a hand mixer, in a metal or glass bowl, beat egg Whites at high speed until fluffy. Set aside.
In a separate bowl, beat the egg Yolks with sugar at medium speed until creamy. Add pineapple juice and vanilla extract, beat well. Add the flour mixture to the creamed mixture. Beat until well combined. Fold in the egg whites with a rubber spatula. Pour cake mixture evenly over the fruit and smooth with the spatula.
Bake for 40 minutes or until the cake is golden and a toothpick inserted into the center comes out clean.
Place on a wire rack to cool for 10 minutes. Run a blunt knife around the edges of the pan to loosen the cake.
Invert carefully onto a flat plate. Serve warm or at room temperature.
*Note: Sifting the flour makes for a lighter cake.