Sweet Potato Soufflé This scrumptious sweet potato soufflé is sweet without being cloying like some sweet potato casseroles can be. A crunchy pecan-and-oat topping nicely complements the creamy sweet potatoes. The casserole requires just 25 minutes of active time to prepare, so you can whip it up for Thanksgiving without a lot of fuss. And the filling can also be made up to five days ahead, so you just have to top it and bake it when it's showtime. With a sweet potato soufflé that's so easy, there's no need to serve it just for the holidays--try it with oven-fried chicken and green beans for a healthy dinner with a Southern accent.