Preheat the oven to 350°F. Spray a non stick metal 13 x 9 inch pan with baking spray.
On the stove top in a small saucepan, melt together 1/2 cup butter with 1 1/2 cups packed brown sugar. Cook just until combined then remove from the heat and spread into the bottom of the prepared pan.
Arrange the pineapple slices on top and place a maraschino cherry in the center of each slice.
In a mixing bowl, cream together the remaining 3/4 cup butter, sugar and vanilla
Add the eggs one at a time mixing well after each addition.
Sift together the cake flour, baking powder and salt. Add to the creamed mixture alternately with the buttermilk beginning and ending with flour.
Spread batter evenly over the pineapple slices. The batter will be thick.
Bake for 50-55 minutes or until a toothpick inserted into the center comes back clean.
Remove from the oven and rest for 5 minutes. Invert onto a serving platter.
Leave the pan on top for a couple of minutes to allow all of the caramel to drip down the sides of the cake.
Serve warm with whipped cream or vanilla ice cream.
Cake flour has less gluten [protein] in it than regular all purpose flour. This makes the "crumb" or texture of the cake more tender. All purpose flour in the same amount will still work but will give the cake a slightly different texture.