Remove it from the fridge about 1 hour before you want to heat it. Reheat covered in foil in a 350º F oven for 20 to 30 mins ...

Layer the potatoes in a 9-by-13 baking dish, seasoning with salt every five or six layers. Pour the remaining maple cream over the sweet potatoes until it comes about ¾ of the way up the potatoes.

Cover with aluminum foil, and bake for about 11⁄2 hours, or until the potatoes are cooked. Heat the broiler. Sprinkle panko over the gratin, dot with 1⁄2-inch cubes of the remaining butter ...