Preheat oven to 375°F. Scrub sweet potatoes and prick all over with a fork. Wrap in foil and bake for 1 hour, or until tender when pierced by a fork. Unwrap potatoes and allow to cool slightly.
When cool enough to handle, cut potatoes in half and scoop out the insides, leaving a quarter inch border on 3 of the potatoes. Discard one skin. Place remaining three sweet potato shells in a baking dish that has been sprayed with non-stick spray.
Add the sweet potato flesh to a food processor with 1 tablespoon butter, cream cheese, 1 teaspoon cinnamon, nutmeg, and 2 tablespoons brown sugar. Process until smooth. Spoon into the sweet potato shells.
In a small bowl, combine topping ingredients with a fork until everything is incorporated with the butter. Spoon over sweet potatoes, lightly patting down to adhere. Bake until topping is golden brown, about 10 minutes.
Recipe can easily be doubled for more servings.
Make-Ahead: Make the potatoes completely ahead (up to the second baking time) and either refrigerate or freeze them in a freezer safe container for up to three months. Thaw overnight in the refrigerator before doing the second bake. You'll need to add five to ten minutes to the baking time to ensure that the potatoes are heated through.