Preheat the oven to 400 degrees F.
Spread the cubed butternut squash on a rimmed baking sheet. Toss with one tablespoon of olive oil and lightly salt. Bake for 25-30 minutes until it is easily pierced with the tip or a sharp knife.
While the squash is roasting, prepare the other vegetables.
Peel the carrots. Remove the top and the bottom (about 1/2 inch) and discard. Cut the carrots into slices and chop.
Chop the onion.
Heat one tablespoon of olive oil in a Dutch oven or large pot over medium-high heat.
Add the onions cooking for 3-4 minutes until they are translucent. Stir regularly. NOTE: If the onions begin to brown too quickly, lower the heat.
Sprinkle the fresh thyme, cinnamon, and cumin over the chopped onion and cook until fragrant, about one minute.
Add the carrots and cook 2-3 minutes.
Add the cooked butternut squash to the pot.
Pour the veggie broth over the vegetables.
Cover and bring to a simmer. Lower to medium heat and cook for about 30 minutes until the vegetables are soft.
Remove the pot from the stove and place on a heat resistant surface (I use a wooden cutting board).
Use an immersion blender or blender to puree the vegetables. See Tips & Tricks for how to use a blender. Insert the blender at various spots in the pot and blend to desired consistency. NOTE: Hots liquids and an immersion blender can be dangerous. Make sure to be cautious when blending the soup.
Stir in the heavy cream.
Lightly salt and pepper the soup to taste before serving.
Serve with a dollop of sour cream if desired. It serves as a nice contrast to the natural sweetness of the soup.