Preheat oven to 350.F. Mix pineapple, sugar, Bisquick, and cheddar in a large bowl. Transfer to a 1 1/2 qt. baking dish, top with Ritz, and drizzle with butter.
Bake until bubbling and Ritz are beginning to brown.
Only used 3/4 c. sugar. Cheese did not melt, despite the bubbling. Baked for an additional 20 minutes (after it was discovered that it hadn't melted, at which point it was room temperature) which melted the cheese some but still not completely. Would double the cook time next time. Despite this, very good.
1 hour is perfect. Added all juice from cans, 1/4 c. Bisquick, 3/4 c. sugar, two tunes of Ritz.