Heat the oil in a soup pot on the stove over medium heat. Add the onions and celery and sauté 4 to 5 minutes until soft and translucent.
Add the carrots, salt, curry powder, cinnamon, garlic powder, turmeric, and pepper. Stir well and sauté for 1 to 2 minutes until fragrant.
Add the butternut squash, apple, and broth. Bring to a boil, then cover and reduce heat to medium-low. Simmer for 20 minutes until the carrots and squash are tender.
Remove from the heat and add the light coconut milk, maple syrup, and vinegar.
With an immersion blender, purée the soup until silky smooth. (Alternately, you can transfer the soup to a stand blender to purée. You may need to work in batches so as not to overfill the blender.)
Taste and adjust seasoning to your tastes.
Serve warm with a garnish roasted pumpkin seeds and a drizzle of extra coconut milk, if desired.