Wash, peel and cut the sweet potatoes into 1/2 inch cubes.
Place sweet potatoes, brown sugar, butter, cinnamon, nutmeg and salt in the bottom of a 4 to 6 quart or larger slow cooker.
Cover and cook on LOW for 6 to 7 hours or on HIGH for 3 to 4 hours or until the sweet potatoes are tender and can easily be pierced with a fork.
Using a potato masher, mash the sweet potatoes to your desired consistency.
Mix in the orange juice.
Cover top of mashed sweet potatoes with marshmallows, recover and cook for an additional 20 to 30 minutes or until the marshmallows are melted.
Serve and enjoy!
* There is much confusion between a yam and a sweet potato. Here in the United States, what you find at your grocery store..that is labeled a yam..is actually a sweet potato. Technically a yam, is a white tuber with little taste, that can only be found normally in ethic stores. We may call those big huge tubers at the store a yam, but they are a sweet potato. * For another variation use pumpkin pie spice instead of the cinnamon and nutmeg. It adds another dimension of flavor!