In this baked oatmeal recipe, I use a 5-inch baking dish. This dish holds about 1.5 cups and has an area of 25 square inches. A 4×6-inch dish has an area of 24 square inches and will work as well. For best results, use a dish of similar size. See our FAQ page for additional information on baking dish sizes. For examples of the dishes used at One Dish Kitchen, please visit our Store page.