Here's a sweet potato casserole that will please everyone in the family, but isn't sticky or cloying. If your guests insist on a traditional marshmallow topping (let's admit that kids love it, and for some adults, it just isn't Thanksgiving without it), see the variation below.
Sprinkle streusel over potatoes. Bake until golden brown, about 40 minutes. Let stand 5 minutes before serving. (Completed dish can be prepared up to 1 day ahead and refrigerated, covered. Remove from refrigerator 1 hour before reheating and let come to room temperature. Bake, loosely covered with foil, until heated through, about 25 minutes.)
06Sweet potato purée with marshmallows: Omit streusel. Spread purée in baking dish, cover with foil, and bake until heated through, about 30 minutes. Sprinkle top with 3 cups miniature marshmallows and broil until marshmallows are lightly browned, about 1 minute. Serve immediately.