Add vegetable stock,garlic, carrot, apple, butternut squash, sage, onion, salt, pepper, cayenne,cinnamon and nutmeg to a small (4-quart) slow cooker or large (6-quart) slow cooker. Toss to combine.
Cook for 6-8 hours on low, or 3-4 hours on high, or until the squash is completely tender and mashes easily with a fork. Remove and discard the sage. Stir in the coconut milk.
Use an immersion blender to puree the soup until smooth. (Or you can transfer the soup in two batches into a traditional blender and puree until smooth, being extremely careful not to fill the blender too full of a hot liquid.) Taste, and season with additional salt, pepper and cayenne as needed.
Serve warm, topped with your desired garnishes.
