Warm the oil in a soup pot on high heat. Add the onions and garlic and cook, stirring, until the onions begin to soften, about 3 minutes.
Add the celery, sweet potatoes, apples, chipotle pepper, adobo sauce, vegetable broth, water, salt, cinnamon, and black pepper.
Cover and bring to a boil, then lower the heat, and simmer gently until the sweet potatoes and apples are soft, about 20 minutes.
Add the apple juice to the pot and puree the soup in a blender in batches until smooth and creamy. Blend in more chipotle peppers, adobo sauce, and/or black pepper, to suit your taste.