Preheat oven to 350°F (175°C).
Pour melted butter into a 9-inch round cake pan and sprinkle with brown sugar.
Arrange pineapple slices over the sugar layer and place a cherry in the center of each.
In a bowl, mix flour, sugar, baking powder, and salt.
Beat in softened butter, milk, vanilla extract, and egg until smooth.
Pour the batter over the pineapple layer and spread evenly.
Bake for 40-45 minutes or until a toothpick inserted in the center comes out clean.
Let cool for 5 minutes before inverting onto a serving plate.