Preheat oven to 350 degrees F. Wash squash and cut into 2" pieces.
Cook in boiling, salted water with sliced onion without covering with water. Boil for 5-8 minutes or until just fork tender. Drain well and PLACE ON BURNER FOR A FEW MINUTES TO EVAPORATE THE REMAINING WATER.
Mash to desired consistency.
Fold in crackers, butter, half & half, sour cream, sugar, 2/3 cup of cheese, and salt & pepper.
Pour into a buttered 9" x 9" x 2" casserole dish.
Add 2/3 cup of cheese as a layer on top of the squash mixture.
Add layer of stuffing on top of the cheese. (A good substitute for the stuffing is bread crumbs from biscuits, buns, etc. that are crumbled and mixed with soft butter).
Bake in preheated oven for about 30 minutes, or until bubbling and beginning to brown.
Remove from oven and layer bacon and french fried onions on top. Serve hot.