Sprinkle flour over pineapple chunks in a medium bowl, and toss to combine. Spread pineapple mixture evenly into a lightly greased 8-inch-square baking dish. Drizzle with reserved 1/2 cup syrup. Top evenly with cheese and cracker crumbs; drizzle with butter.
Bake at 350° for 25 to 30 minutes or until browned. Serve immediately.
Note: For testing purposes only, we used Ritz crackers.