Preheat oven to 350 degrees. With the 1 tablespoon butter, grease the bottom and sides of a 9 x 13 baking dish. Evenly spread the 2 tablespoons brown sugar on the bottom of the pan over the butter.
Dump the pineapple and the cherry pie filling into the pan, stir and spread evenly. Spread the cake mix evenly over the top.
Cut the 1 ½ sticks of butter into small pieces and place evenly over top of the cake mix.
Bake for 50 minutes to 1 hour or until the top is golden brown.