In a dutch oven, heat the olive oil over medium heat. Add the apple and onion and cook, stirring occasionally, until tender, about 7 minutes. Stir in the sweet potatoes and stuffing and cook to heat through. Add the broth and bring to a boil; season with salt and pepper. Lower the heat and simmer for 20 minutes. Using a food processor or immersion blender, puree the mixture.
Meanwhile, in a small bowl, combine the yogurt and cranberry sauce. To serve, dollop the soup with the cranberry cream.