Slice butternut squash in half. Remove seeds and stringy bits. Put one squash half on a baking sheet flesh side up. Drizzle olive oil on top. Roast at 400°F for 40 minutes, or until fork-tender. After squash cools, peel skin off.
Heat tablespoon of olive oil in a large pot. Add chopped onion. Cook until translucent. Add garlic and ginger, and cook a minute longer.
Add coconut milk, curry paste, vegetable broth, peanut butter, salt and pepper and cook about 10 minutes so flavors meld together.
In a blender, combine butternut squash and curry broth mixture. Mix until smooth.
Return soup to the stove. Bring to a simmer to heat through.