Preheat your oven to 425º F.
Remove the stems from the pumpkins, then cut them in half. Scrape out the seeds. Then, brush the inside of the pumpkins with olive oil and season with salt and pepper. Place them cut side down on a baking sheet, and bake for 30-40 minutes, until they are soft and golden brown.
Once the pumpkins are cool enough to handle, scoop out the flesh. It should yield about 6 cups.
Heat the olive oil in a large pot over medium heat. Saute the garlic for about a minute, until it becomes fragrant. Then, add the onions and saute for about 5 minutes, or until the onions are translucent. Add the cumin and cook for another minute to release all of its flavor.
Add the pumpkin and the remaining ingredients to the pot, except the sour cream. Bring it to a soft boil, and cook it for 10 minutes.
Let the soup cool slightly, then add it to a blender along with the sour cream. Blend it until smooth. (If you have an immersion blender, you can use that instead).
Garnish the soup with roasted pepitas and extra sour cream (optional). Enjoy!
