Preheat the oven to 375 Line a baking sheet with a generous amount of foil. Add the butternut squash and sweet potatoes. Drizzle on the olive oil and on the potatoes, mix it around with your hands to incorporate the oil. Sprinkle salt and pepper to taste; toss on the rosemary sprigs.
Cover the pan with foil and fold the sheets under.
Bake the vegetables in this foil pouch for about 45 minutes until the they are tender.
Heat a large pot over medium heat, add 2 Tablespoons of olive oil, the onion, garlic, and sugar and caramelize.
When veggies are roasted, scoop the roasted butternut squash out of its shells and add them,along with the sweet potatoes and carrot, to the pot with the caramelized onions.
Add the spices and salt and pepper to taste. Add the broth and simmer for about 30 minutes. Puree until smooth; if texture is too thick, add a bit of water (you can puree in a blender or with an immersion blender). Adjust seasoning to your taste. Sprinkle on some pepitas and a little extra spice.