Preheat your oven to 350F and prepare your baking dish with cooking spray.
In a large bowl combine the sugar, all-purpose flour, and reserved pineapple juice. Add the drained pineapple chunks and toss to combine. Spoon the pineapple mixture into the prepared casserole dish and top with the shredded cheddar cheese. Set aside.
In a medium bowl combine the buttery cracker crumbs with melted butter and stir to coat. Sprinkle the crumbs over the pineapple evenly.
Bake for 30 minutes or until the top is golden brown and pineapple mixture is bubbling.