1. Place squash in pot,cover with water and bring to a boil. Reduce heat,cover and simmer 20-25 mins.
2. Drain well,place in large bowl and mash. In another bowl,combine mayo,onion,egg,sugar and squash.
3. Mix well,transfer to greased 1Qt. baking dish
4. Combine cracker crumbs,cheese and butter. Sprinkle on top and bake uncovered at 350 degrees for 30-40 mins. or until heated thru and browned..