In a large saucepot, melt the butter over medium heat. When the butter begins to bubble, add the carrots, celery and onions.

Cook, without color, for about 10-12 minutes. Add the squash, apples, stock and cinnamon. Bring to a boil, then simmer for 25-30 minutes or until the squash is tender.

In small batches, blend the soup thoroughly. Season with salt and pepper.