Preheat your oven to 400°F (200°C). Spread the cubed butternut squash on a baking sheet, drizzle with olive oil, and toss to coat evenly.
Roast the squash in the oven for about 25-30 minutes until tender and caramelized around the edges, filling your kitchen with a sweet, nutty aroma.
While the squash roasts, heat a large pot and add a splash of olive oil. Sauté the chopped onion until it becomes soft and translucent, about 5 minutes, and smells slightly sweet.
Add the grated ginger to the onions and cook for another 1-2 minutes until fragrant, being careful not to overcook to avoid bitterness.
Transfer the roasted squash into the pot with the ginger and onion mixture, stirring gently to combine.
Pour in the vegetable broth, then bring the mixture to a gentle simmer. Add cayenne pepper, salt, and pepper to taste. Let it simmer for 10-15 minutes to let flavors meld.
Use an immersion blender directly in the pot to blend the soup until completely smooth and velvety. Alternatively, carefully transfer to a blender and purée in batches.
If desired, stir in coconut milk or heavy cream for extra creaminess, and adjust seasoning with more salt, pepper, or spice if needed.
Once blended and heated through, ladle the soup into bowls. It should pour smoothly and have a bright orange color, with a rich, silky texture.
Garnish with a drizzle of coconut milk, a sprinkle of chili flakes, or fresh herbs if desired. Serve hot for a cozy yet vibrant bowl of soup.
