Heat oven to 350°F
Pour the melted butter in a 9 inch square pan and then evenly sprinkle with the brown sugar. Arrange pineapple slices over the brown sugar. Place a cherry in center of each pineapple slice.
In a medium bowl, whisk together the flour, baking powder, and salt.
In a large mixing bowl or the bowl of a stand mixer with the whisk attachment, beat butter until creamy. Add the sugar and beat until light and fluffy.
Add the eggs one at a time, beating until well combined. Beat in the vanilla extract.
Beating on low speed, add a third of the flour, milk and pineapple juice beating just until combined. Continue alternating with the remaining flour, milk, and juice until well combined.
Pour the cake batter over the pineapples. Bake for 45 to 50 minutes or until toothpick inserted in center comes out clean. Let the cake cool for 5-10 minutes and then top the pan with a plate, pan or serving dish, then carefully flip the cake/dish over. Serve warm and ENJOY!