Lightly spray or grease the bottom of 9x13 pan. Drain 1 large can (1 lb 4 oz) of crushed pineapple. Dump & spread evenly in bottom of pan. On top of pineapple, dump & spread a can of cherry pie filling. Sprinkle a yellow cake mix over this. Drizzle ½ cup of melted butter or margarine over the top. Bake 50-55 min. at 350 degrees. Sprinkle chopped nuts over top, last 15 min.