I'm not sure there are more variations of any other dish --- with marshmallows and without, mashed and sliced, and more options for toppings than a sundae bar. This recipe has the sweet potatoes covered with a crunchy streusel topping. Bake the potatoes the day before, assemble them in the baking dish, cover and store in your fridge. You can also make the topping the day before and store in a covered container in your fridge. Thanksgiving morning, take the potatoes out of the fridge and let them sit on your counter until they're room temp, about an hour. Then top them with the streusel and bake.
TIME SAVING TIP: Peel and cube the sweet potatoes and cook until fork tender in a large pot of boiling water. Mash, using a potato masher, with the butter until smooth. Then follow the rest of the directions to finish the dish.