Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.
Toss the pumpkin chunks with about 1 tablespoon of olive oil and spread them out in an even layer. Roast in the oven until they're tender and caramelized around the edges, about 25-30 minutes. You’ll notice a sweet, fragrant aroma filling the kitchen.
While the pumpkin roasts, chop the onion and mince the garlic. In a large heavy-bottomed pot, heat the remaining tablespoon of olive oil over medium heat. Add the onion and cook until it becomes translucent and soft, about 5 minutes, filling your space with a sweet aroma.
Add the minced garlic to the onions and cook for another minute until fragrant. Be careful not to burn the garlic, as this can add a bitter note to your soup.
Once the pumpkin is roasted and cool enough to handle, peel off the skin if necessary and add the pumpkin flesh to the pot. Stir everything together so the flavors combine.
Pour in the warm vegetable broth, stirring to combine. Bring the mixture to a gentle simmer and let it cook for about 10 minutes, allowing the flavors to meld and the soup to warm through.
Remove the soup from heat and use an immersion blender to carefully blend until smooth and creamy. Or, transfer the mixture to a blender in batches, blending until silky, then return to the pot.
Stir in the coconut milk or heavy cream for richness. Taste the soup and season with salt, pepper, and a pinch of allspice or cinnamon if desired. Adjust seasonings to your preference.
Gently reheat the soup if needed, stirring often, until steaming hot and full of flavor. Watch for a velvety texture with a slightly chunky consistency if some pumpkin pieces remain.
Serve the warm pumpkin soup with a drizzle of olive oil or a sprinkle of herbs. Enjoy its comforting aroma and rich, velvety texture as the perfect feature of fall.
