How can I prepare a delicious sweet potato casserole ahead of time?

To prepare a delicious sweet potato casserole ahead of time, you can peel, chop, and cook the sweet potatoes until they are soft. MASH them with butter, sugar, and spices, then transfer the mixture to a baking dish. Cover and refrigerate the casserole until you are ready to bake it. Before serving, top the casserole with a crunchy topping of pecans, marshmallows, or a mixture of both, and bake until heated through and golden brown.