Preheat the oven to 350 F.
Grease a 1 ½ quart (9x9) baking dish.
In a large bowl, combine the pineapple, sugar, flour, and cheese. Mix to combine.
Spoon into the greased casserole dish.
In a small bowl, combine the cracker crumbs and melted butter. Feel free to add in the pineapple juice if the mixture seems dry.
Spread over the top of the pineapple casserole.
Bake at 350F for 25-30 minutes or until bubbly and the top is golden brown.
Remove and let cool slightly.
Serve warm.