Preheat the oven to 350°F (175°C)
Grease a 9-inch round cake pan or 9×13-inch baking dish
Melt 1/4 cup butter and pour it into the bottom of the pan
Sprinkle 1/2 cup brown sugar evenly over the butter
Arrange pineapple slices over the brown sugar
Place maraschino cherries in the centers of the pineapple slices, if desired
In a bowl, whisk together 1 1/2 cups all-purpose flour, 1 cup granulated sugar, 2 teaspoons baking powder, and 1/2 teaspoon salt
In another bowl, mix 1/2 cup milk, 1/4 cup pineapple juice, 1/2 cup melted butter, 2 eggs, and 1 teaspoon vanilla extract
Combine the wet and dry ingredients and mix until just smooth
Pour the batter evenly over the pineapple layer
Bake for 35 to 45 minutes, or until a toothpick inserted in the center comes out clean
Cool the cake in the pan for 10 to 15 minutes
Invert the cake onto a serving plate
Serve warm or at room temperature