Add the onion, carrot, apple, butternut squash, garlic, 1 ½ teaspoons salt, turmeric, cinnamon and stock to a 6-quart slow cooker.
Cover and cook on high for 4-5 hours, or on low for 6-7 hours, or until the butternut squash is very tender.
Uncover and add the coconut milk or cream and ½ teaspoon salt.
Using an immersion blender, blend until very smooth. Alternatively, working in batches, carefully ladle the soup into a blender and blend on high until smooth.
Add the apple cider vinegar, stirring to combine. Taste and add additional salt if desired. Serve with any toppings you like.
