Preheat oven to 350 degrees. Place butternut squash on a cookie sheet and give it a few pokes with a knife, then place in oven. Bake for 1 hour, or until browned, and knife easily slides in. Remove from oven and let cool for a couple minutes.
Carefully cut off ends of squash, then slice lengthwise. Remove and discard seeds, then scoop the squash out, and place in a blender.
Add all other ingredients to the blender, then blend until smooth and creamy (adding any additional, equal amounts of coconut milk and broth to reach desired consistency). Taste test, and add more salt and/or curry powder if desired.
Pour into bowls, and top with optional chopped cashews, and serve.