Bring a large pot of water to a boil then add your washed sweet potatoes for about 30 minutes, or until cooked. You should be able to easily pierce the potato to the center with a fork.
Immediately after the potatoes are cooked, remove from the hot water and place in an ice water bath. This should make the skin of the potatoes easy to remove with your fingers and simply slide off.
Preheat your oven to 375 degrees, and have your casserole dish on hand. A 9x13-inch pan gives more surface area for topping if desired.
Using a mixer or some muscle, combine the peeled sweet potatoes, eggs, salt and cinnamon until well combined and fluffy.
Spread the sweet potato mixture into the pan, then add your pecans, brown sugar and then the melted butter on top. If adding marshmallows, simply spread them on top about three minutes before removing the soufflé from the oven, and keep a close eye on them to avoid burning.
Bake for 25 minutes uncovered, then serve warm.
Keyword Side Dish, Sweet Potato Casserole, Sweet Potato Souffle