Heat oven to 400°
Pierce each sweet potato several times with the tines of a fork.
Place the sweet potatoes on a rimmed baking sheet lined with foil.
Bake until tender, about 45 minutes.
Remove from oven, set aside to cool.
Turn oven down to 350°.
When sweet potatoes are cool enough to handle, peel off the skins.
Place sweet potatoes in a large mixing bowl, mash with a potato masher.
Blend together sweet potatoes, brown sugar, salt, marshmallow fluff, vanilla extract, nutmeg, cinnamon, ginger, evaporated milk, butter and dried cranberries.
Spoon into a buttered 2 quart baking dish.
Bake at 350° for 45 minutes.
Top sweet potatoes with mini marshmallows.
Return back to the oven, bake an additional 15 minutes longer.
Marshmallows should be a nice golden brown.