Preheat your oven to 400°F.
Line a baking tray with parchment paper and evenly distribute peeled squash cubes and chopped onion across the sheet.
Drizzle the olive oil over the squash and onion and season with garlic powder, salt and pepper.
Roast the butternut squash in the oven for about 30 minutes, or until it's fork tender.
In a large soup pot or Dutch oven over medium-high heat, pour in the chicken bone broth and let it come to a boil.
Remove the squash and onion from the oven and add to soup pot of bone broth. Bring the mixture to a simmer and let it cook for about 15 minutes then turn off heat.
Use an immersion blender to puree the soup directly in the pot until it's smooth and creamy. If you don't have an immersion blender, you can carefully transfer the soup in batches to a regular blender and blend until smooth, then return it to the pot.
Ladle the butternut squash soup into bowls. Serve with crusty bread or croutons.