To make this Cheesy Southern Squash Casserole gluten-free. Simply swap out the all-purpose flour. For a gluten-free alternative, like a 1-to-1 baking mix. Which will keep the texture of the casserole intact. For the topping. Use gluten-free crackers. Which are widely available. In most grocery stores. These easy substitutions. Will allow you to enjoy. The creamy, cheesy goodness of this casserole. Without compromising on flavor!