Pour in the vegetable broth, add sweet potatoes and apple. Season with salt and pepper. Bring to a boil then reduce heat to low; cover and simmer for 20-25 minutes until sweet potatoes are tender.
Blend the soup until smooth using a blender or immersion blender. Return to heat if needed.
Stir in coconut milk if desired for extra creaminess. Adjust seasoning as needed.
Serve hot with toppings like toasted pumpkin seeds or fresh cilantro.