Preheat oven to 350 degrees.
Pour melted butter into the bottom of a 10 inch deep dish cake pan and sprinkle the brown sugar evenly over top.
Arrange the pineapples and cherries on top of the butter mixture and up the sides, if desired. Set aside.
In a medium bowl, whisk together the flour, baking powder and salt. Set aside.
In a large bowl, beat the brown sugar and butter together until smooth. Turn the mixer to low and, slowly add the milk, vanilla, egg and pineapple juice until combined.
Add the dry ingredients to the wet mixture beating until combined and no lumps remain.
Pour the batter over the pineapple and spread evenly — some of the fruit may poke through the batter.
Bake for 45 minutes or until golden brown and the top springs back when pressed with your finger.
Allow the cake to cool in the pan for 5 minutes then turn the cake out onto a cake plate or platter and leave the pan on the cake for 10 minutes longer.
Remove the pan and allow to cool to room temperature or serve warm, if desired.