Preheat oven to 400 degrees F (200 C).

In a large bowl, combine the butternut squash, olive oil, Italian spices, salt, and garlic powder. Mix together, coating the squash well. Spread out on a rimmed baking sheet.

In the same bowl that the butternut squash was in, toss the apple slices, onion, and carrots to coat oil and spices. Place on a second rimmed baking sheet. Place both baking sheets in the oven and roast for 35-40 minutes.

Heat up olive oil over medium heat in a large pot on the stove. Add the roasted ingredients and then the vegetable stock. Add salt and more spices to taste. Bring to a boil, then reduce heat to low and simmer, covered, for 20 minutes.

Using an immersion blender, combine all ingredients until smooth, or transfer to a blender to puree. Serve warm. Garnish with additional chili flakes, ground pepper, or Italian spices.