Cinnamon Squash Chowder

This recipe comes from OhSheGlows.com, where it is called Luxurious 7-Vegetable and "Cheese" Soup.  It does not taste like 7 vegetables or cheese to me, so I call it what I think it tastes like instead. I've tried it seasoned a couple different ways, but everyone in my family (baby included) found the cinnamon to be essential.

Ingredients

1 tablespoon extra virgin olive oil (optional)

2-3 cups chopped sweet onion (from 1 large onion)

3 large garlic cloves, minced

1 cup chopped celery (from 2-3 stalks)

1 heaping cup peeled and chopped carrots (from 2 small carrots)

6 packed cups broccoli florets (from 1 large bunch broccoli)

2 cups peeled and chopped sweet potato (from 1 small sweet potato, about 320 g)

1.5-2 cups seeded and chopped Delicata squash (from 1 very small squash about 275 g) (I like to substitute butternut squash, or whatever squash needs using up)

6 cups vegetable broth

5 tablespoons nutritional yeast

1/4 teaspoon cinnamon

Salt and pepper, to taste

Directions

1. Grab a very large pot (about 6.5 qt) with a lid and set aside.
2. Add the onion and garlic with the oil into the pot and saute over medium heat for a few minutes. Season with a couple pinches of salt and pepper.
3. Add the celery, carrots, broccoli, sweet potato, and squash, one by one, as you chop them. Continue to saute over medium heat, stirring every once and a while so it doesn't stick to the bottom.
4. Cover the pot with a lid and cook the vegetables for 4-5 minutes, reducing heat if necessary.
5. Remove lid and stir in the broth. Bring the soup to a low boil. Reduce heat to low/medium and cover with lid. Simmer for 10-15 minutes, until the squash and potato are fork tender.
6. Turn off heat and remove lid. Add in the nutritional yeast and cinnamon. Puree with an immersion blender (or let cool and blend in batches if necessary). Season with salt and pepper. 
7. Sprinkle with cinnamon for garnish and serve warm. 

[Edited 12/1/2013:  To make this a no-oil recipe, you can skip sauteing the vegetables and just boil them in the broth -- I made this in a rush last week and forgot to saute, and I couldn't tell the difference in flavor.  The essential point here is to make sure the squash and sweet potatoes are diced small enough that they will cook in a reasonable amount of time.  To that end, I boiled the soup about ten minutes with a lid on the pot, and everything turned out just fine.  Boiling much longer would have destroyed the broccoli though.]