To prepare the potatoes, preheat the oven to 400°F. Pierce the sweet potatoes with a fork, wrap them in aluminum foil, and bake until they are easily pierced with a fork.
To prepare the casserole, preheat the oven to 350°F. Blend the baked sweet potatoes, along with the other casserole ingredients, until smooth, for about 30-60 seconds. Pour the mixture into a glass baking dish, ensuring you scrape out as much filling from the blender as possible.
Next, combine the topping ingredients in the blender or food processor and pulse until it forms coarse breadcrumbs. Sprinkle this mixture over the casserole's top and bake for 40-45 minutes until it turns golden brown.