Preheat oven to 350. Wash and slice squash into 1/4 inch slices. Saute squash, carrots and onions in 6 Tbsp. of butter. Liberally salt while cooking and sprinkle a fine layer of garlic powder about 3 times while turning veggies over in skillet. Mix together sour cream and cream of chicken soup. Prepare stuffing according to instructions on box and let sit while squash is cooking.
When squash reach your desired texture, drain all liquid out of skillet and stir in the soup/sour cream mixture. Mix well.
Spread a layer of stuffing on the bottom of a greased casserole dish or 13x9 baking pan. Spread squash mixture over stuffing layer and then finish with stuffing on top of it all. Bake for 25 minutes.