Preheat your oven to 400°F (200°C). Spread the cubed butternut squash on a baking sheet, drizzle with a tablespoon of olive oil, and toss to coat evenly. Poke a few holes in the squash with a fork to prevent bursting during roasting. Roast until golden and caramelized around the edges, about 20 minutes.
While the squash is roasting, heat the remaining tablespoon of olive oil in a large pot over medium heat. Add the chopped onion and sauté until soft and translucent, about 5 minutes. The onions should smell sweet and turn a light golden color.
Add the minced garlic to the onions and cook for another minute, until fragrant. Be careful not to burn the garlic—stir continuously as you smell a warm, aromatic note filling the kitchen.
Once the roasted squash is cool enough to handle, transfer it to the pot with the onions and garlic. Add the broth and bring the mixture to a gentle simmer. Let it cook for about 5 minutes to meld the flavors.
Use an immersion blender to purée the soup directly in the pot until smooth and velvety. Alternatively, transfer the soup in batches to a blender, then return it to the pot. Blend until silky and even in texture, with no chunks remaining.
Stir in the heavy cream for extra richness, then season with salt and pepper to taste. Warm the soup over low heat for a few minutes, just until heated through, while tasting and adjusting seasoning if needed.
Pour the soup into bowls, and serve warm. Garnish with a drizzle of cream, toasted seeds, or fresh herbs if desired. Enjoy the comforting warmth and rich caramel notes in every spoonful.
