Preheat your oven to 350 degrees, and butter a 2 quart casserole dish. Blend together 6 tablespoons of pineapple juice, sugar, flour, & melted butter in a mixing bowl.
Add in the pineapple & cheese; mix well & pour into your casserole dish. Bake for 20 minutes.
Remove from the oven. Mix the crushed crackers & melted butter together; sprinkle on top. Reduce the heat of the oven to 300 degrees, and bake the casserole for an additional 20 minutes.
Let cool for 5 minutes before serving.