Preheat the oven to 325 degrees. Stir together the melted butter, brown sugar and corn syrup and evenly coat the bottom and sides of a 10-inch glass pie plate with the mixture. Arrange pineapple on top.
In a mixing bowl, combine the pastry flour, granulated sugar, baking powder, baking soda and salt and thoroughly mix. In another bowl, whisk together the softened butter, sour cream, egg yolks and vanilla. Add to the dry ingredients and mix with an electric mixer at medium speed about 1 1/2 minutes, scraping down the sides of the bowl occasionally, until thick and smooth. Using a spatula, spread the batter evenly over the fruit, building up the outside edges so the cake will be level when baked.
Bake 40 to 50 minutes, until golden brown and a tester inserted in the center comes clean. Transfer to a rack to cool 3 to 5 minutes (no longer) and then invert onto a serving plate, repositioning the fruit as necessary.