In a large bowl, using a potato masher, mash the potatoes and pineapple together. Add in the margarine, salt, nutmeg, pepper, and egg, mix well.
Mix in 1 cup of cranberry sauce.
Coat 8 one quart casserole dishes with nonstick cooking spray and spoon 1/3 cup of sweet potato mixture into each. Place 1 tablespoon of cranberry sauce on top of each mini casserole and bake for 40 minutes.