Preheat oven to 350 degrees.

Cook squash in boiling salt water until tender and drain.

In saucepan, cook carrots and onions in 1 T. butter until tender. Remove from heat.

Stir in 1-1/2 c. stuffing mix, soup and sour cream. Gently stir in squash.

Turn into ungreased 1-1/2 quart casserole dish.

Melt remaining butter and add remaining stuffing. Toss gently and top casserole with mixture.

Bake for 35-40 minutes.