Preheat oven to 375 degrees F. Place potatoes in 13 x 9 x 2-inch glass baking dish. Combine butter, sugar, cinnamon, nutmeg, ginger and salt in small saucepan over medium heat. Bring to boil and stir until sugar dissolves. Pour this mixture over sweet potatoes and toss to coat. Cover dish well with foil.

Bake 50 minutes. Uncover and continue to bake until potatoes are tender and syrup thickens a bit (basting occasionally) about 20 minutes. Raise oven temperature to 500 degrees F. Top sweet potatoes with cubed marshmallows and pecans and bake until marshmallows begin to melt and nuts begin to brown, about 3 minutes.

Courtesy of Whole Foods Market.