Preheat the oven to 375°F/190°C
In a medium-sized mixing bowl, sift the cake flour, baking powder, and salt together. Set aside.
In a large mixing bowl, using an electric hand mixer with beaters attached, add the egg yolks and beat until light and fluffy, about 3 minutes.
To the yolk mixture, gradually add the white sugar and continue to beat the yolk/sugar mixture until well combined., another 2-3 minutes.
To the egg yolk mixture, alternately mix in the pineapple juice and sifted flour mixture. Set the cake batter aside.
In the bowl with the egg whites, use a hand mixer with beaters attached, whip the egg whites until stiff peaks form, about 4 minutes. A stand mixer with a whisk attachment can also be used. Fold whipped egg whites into the cake batter and set the bowl aside.
Place the cast iron skillet over medium heat and melt the butter in the skillet. Spread the brown sugar evenly over the melted butter.
Place the pineapple slices on top of the brown sugar.
Put a whole maraschino cherry in the center of each pineapple slice. Fill the spaces around the pineapples with pecans.
Pour the prepared cake batter over the pineapples.
Place the cast iron skillet into the preheated oven. Bake at 375°F for 30-35 minutes. To check for doneness, use either a cake tester or a toothpick. The skewer should come out clean with no wet batter on it.
Let the cake cool 10-15 minutes on a wire cooling rack.
Slide a butter knife around the edges of the cake to loosen it.
Carefully flip the pan upside down on top of a large cutting board or cake plate. Carefully left the skillet and the cake is ready to be served.
Slice and serve warm. Store any leftovers in the fridge in a covered container for 2-3 days.