Place the chopped squash in a medium-size mixing bowl. Drizzle the squash with 2 tablespoons of olive oil and season with 1/4 teaspoon of salt and 1/8 teaspoon black pepper.
Line a sheet pan with parchment paper or aluminum foil and place the squash on top of the sheet pan. Set the sheet pan into the oven and roast for 30 minutes, or until the squash is lightly caramelized and tender.
Remove the squash from the oven and set aside. Place a 1-gallon saucepan over medium high heat and add the remaining 1 tablespoon of olive oil to the pan. Add the onions, carrots, celery and leeks in the pan and sweat, stirring often for 5 to 7 minutes.
Add the shallots and garlic to the pan and sweat for 5 minute stirring continuously. Deglaze the pan with the vinegar and add the chicken stock to the pan. Place the squash in the pan with the maple syrup and sage and spices.
Bring the pan to a boil and reduce to a simmer. Continue to cook the soup for 30 minutes, or until the vegetables are all tender.
Use an immersion blender to puree the soup to a smooth consistency and velvety texture. Alternately, you can puree the soup in batches using a blender. Taste the soup and re-season if necessary with 1/2 teaspoon of salt and 1/8 teaspoon pepper. Keep warm until serving.
(Optional) Drizzle with Pumpkin Seed Oil before serving