1. Preheat oven to 350 degrees.
2. Spray a small casserole dish with a non stick cooking spray.
3. Dump the pineapple chunks including the juice, sugar, and flour into a large bowl and mix well.
4. Melt butter over low heat in saucepan, then stir in the crushed crackers until coated.
5. Spread the pineapple mixture into the prepared casserole dish.
6. Sprinkle the cracker-butter mixture over the top of the pineapple.
7. Bake 25 minutes or until lightly browned on top.