1. Rinse sweet potatoes in cold running water and pierce with a fork.
2. Microwave sweet potatoes on full power until tender, about 15 minutes. Turn them half way during baking.
3. Preheat oven to 400 degrees. Remove skin from sweet potatoes and mash with hand beaters or food processor. Add the rest of the ingredients and mix until smooth.
4. Pour mixture in an 8 inch square baking pan. Bake until casserole is firm in the center, about 40 minutes.
5. Remove pan from oven. Allow to stand for 5 minutes then cut into 10 squares.
6. Serve hot. Refrigerate leftovers.
You may want to experiment with using canned sweet potatoes.