Preheat oven to 400°.
Wash and dry the outside of the squash. Cut in half, length wise, and scoop out the seeds.
Drizzle the cut side with one tablespoon of olive oil and sprinkle with salt and pepper.
Place squash halves, cut side down, on a rimmed baking sheet and roast for 30-40 minutes, or until is it very soft and the skin bubbles. Make sure to test the thickest part of the squash (i.e. the end without the seed cavity). A fork or knife inserted in the skin should go through the squash easily.
Remove from oven and cool. Peel away the skin.
Sauté the onions with the remaining tablespoon of olive oil in a soup pot over medium-low heat. Cook for 4-5 minutes. Add garlic, thyme and crushed red pepper flakes and continue cooking for 1-2 minutes. Slowly add the vegetable or chicken stock and bring to a simmer over medium heat for 5-10 minutes. Add squash and return to simmer.
Purée soup with an immersion blender until smooth. (Also, see text above for alternate methods of puréeing.
Serve with cashew cream and toasted pumpkin seeds or cashews.