Heat the oil in a large pot over medium heat. Add the onion, salt, and several grinds of pepper and sauté until soft, 5 to 8 minutes. Add the sweet potatoes and the apple and cook until they begin to soften, stirring occasionally, about 8 to 10 minutes.

Add the garlic, ginger, coriander, and smoked paprika and stir. Stir in the apple cider vinegar and then 3 cups of the broth and the coconut milk. Bring to a boil, cover, and reduce the heat to a simmer. Cook until the potatoes are tender, 20 to 30 minutes.

Let cool slightly and pour the soup into a blender, working in batches if necessary, and blend until smooth. If your soup is too thick, add up to 1 cup more broth and blend. Season to taste and top with a swirl of coconut milk, pepitas, cilantro, and Aleppo pepper, if desired. Serve with crusty bread.