1. Peel and cut sweet potatoes into pieces about 1 inch square. This is an approximation. The smaller the pieces, the quicker they will get soft.
2. Place the pieces of sweet potato in a large saucepan.
3. Add cold water to cover all of the potatoes.
4. Bring the water and sweet potatoes to a boil over high heat.
5. Lower the heat, cover and simmer 20 to 30 minutes or until tender.
6. Drain the potatoes.
* Start here if you are using canned or microwaved potatoes *
7. Preheat oven to 350 degrees.
8. Place potatoes, brown sugar, maple syrup, cream, butter, vanilla, and spices in a large bowl.
9. Beat until smooth and fluffy. You can use a potato masher to mash down the mix and then a fork or egg beater to whip the potatoes, or just use an electric mixer.
10. Transfer the whipped sweet potato mixture into a greased 13x9-inch or 3-quart baking dish. Top evenly with marshmallows.
11. Bake the potatoes uncovered for about 25 minutes or until heated through. The marshmallow topping should be golden brown, not burnt.
The sweet potatoes can be cooked in a microwave instead of boiling. It goes a bit quicker that way and doesn't change the taste.
If you plan to cook potatoes - or sweet potatoes - in a microwave, make sure to stick each potato two or three times with a fork so excess steam can escape while cooking. Otherwise they'll explode!
Microwave the sweet potatoes on High for 3 to 6 minutes. Turn the potaoes over (careful, they'll be hot) and finish cooking for another 2 to 4 minutes -- until they are tender.
Let the microwaved potatoes sit for 5 minutes or until they are cool enough to work with. Peel the skin and begin the recipe from step number 7.