Preheat oven to 350 degrees. Grease bottom and sides of 9x13-inch pan. Spread drained pineapple on bottom, then sprinkle half pkg. cake mix and a layer f pecans. Sprinkle remaining cake mix on top. Dab with butter or margarine and bake tor 50 minutes-1 hour. Cool and cut into squares. Makes 6-8 servings.