Preheat oven to 375 degrees F.
On a baking sheet; combine cut squash, sliced onions, and diced pears. Sprinkle with salt and drizzle olive oil to lightly coat and toss mixture.
Bake in the oven until onions begin to brown, about 8-10 minutes. Toss vegetables and continue cooking until squash is fork tender, about another 8-10 minutes.
Remove vegetables from the oven. Take half of the vegetable mixture and place it in the blender. Add one quart of stock and blend until well combined. Pour soup into a large pot. Repeat with the balance of the vegetables, and the remaining stock, and pour into the pot. Add the cinnamon stick and simmer the soup for 30 min.
Garnish option - add a thinly sliced cooked pear to the top of each bowl.