Preheat oven to 350*F. Butter 9X13 inch baking dish.
Place sweet potatoes in pan of water and bring to boil. Cook until tender but still firm. Brain and transfer to a large bowl to cook. Peel and cut into pieces. If canned sweet potatoes, cut into smller uniform pieces if desired.
In a small pan, combine pineapple, sugar, and spices. Bring to a boil and reduce heat.
Pour sauce over potatoes and gently mix. Place in prepared pan. May cover and refrigerate or bake. Bake 30 to 45 minutes, placing marshmallows on top of casserole during last few minutes of baking to melt.