Thanksgiving tradition
Drain canned sweet potatoes thoroughly to remove excess moisture before mashing, preventing ice crystal formation during freezing. Cover the unbaked dish tightly with two layers of plastic wrap followed by aluminum foil for storage up to three months. Thaw the casserole overnight in a refrigerator held at 40 degrees Fahrenheit before proceeding to the baking phase. Bake uncovered at 325 degrees Fahrenheit until the interior reaches 165 degrees Fahrenheit and the topping turns golden brown.
Crush corn flakes slightly rather than reducing them to powder to maintain structural integrity under thermal stress. Combine the crushed cereal thoroughly with melted butter and sugar to coat every flake completely. Add this crunchy topping immediately before baking to prevent moisture migration from the potatoes from rendering the cereal soggy.
Reheat individual leftover portions in a 350-degree oven for 15 minutes to re-crisp the cereal layer. Avoid microwave reheating, which drives moisture upward and liquefies the crisp exterior texture.