Heat the oil in a large pot over medium heat.

Sauté onions 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 salt, garlic, ginger, coriander, smoked paprika, and cayenne (optional).

Stir in 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 and parsley.

Serve with crusty bread.