Melt butter in bottom of non stick baking pan. Sprinkle the bottom of pan with brown sugar. Place sliced pineapple on top, then put cherries in the center of the pineapple. Mix cake as directed on box. Pour on top. Bake in oven 350 degrees, for 35 or 45 min. Depending on size of pan. Let cool, then flip it over on a serving dish.