Preheat oven to 350°F (175°C).
Pour melted butter into a 9-inch round cake pan. Sprinkle brown sugar evenly over the butter.
Arrange pineapple slices over the brown sugar. Place a cherry in the center of each pineapple slice.
In a mixing bowl, whisk together flour, sugar, baking powder, and salt.
Add softened butter, milk, vanilla extract, and eggs to the dry ingredients. Beat until smooth.
Pour the batter over the pineapple slices in the cake pan.
Bake for 45 minutes or until a toothpick inserted into the center comes out clean.
Let the cake cool in the pan for 5 minutes. Run a knife around the edges to loosen, then invert onto a serving plate.