To make the Pineapple layer:Melt the butter in a cast iron skillet or a medium saucepan over medium heat. Add brown sugar and cook, whisking to remove all clumps. About 1 minute. If using cast iron skillet place pineapple slices and maraschino cherries to desired arrangement. If using a baking pan, transfer the caramel syrup to baking pan and decorate with pineapple slices and maraschino cherries as preferred.

To make the Cake Layer:Place a rack in the center of the oven and preheat the oven to 350 degrees F. Sift together the dry ingredients: cake flour, baking powder, and salt. In a small bowl, whisk together the buttermilk, vanilla extract, and pineapple syrup. Set aside.

Beat the butter and sugar on medium speed in an electric mixer fitted with a paddle attachment or with a hand mixer until light and fluffy, about 3 minutes. Add yolks one at a time and allow them to be incorporated completely. Reduce speed to low and add flour mixture and buttermilk mixture alternately in 3 batches, beginning and ending with flour mixture and mixing until just combined.

Pour the batter into the cast iron skillet or baking pan and bake until puffed and pale golden, about 25 - 30 minutes or until a toothpick inserted in the center comes out clean or with just a few crumbs. Mine took 27 minutes. Cool cake completely before loosening the sides and flipping onto a plate. Serve warm or at room temperature.