Surprise your guests with the earthy and rich flavor of bourbon in this delicious sweet potato casserole for Thanksgiving. Preheat oven to 350 degrees F. Arrange sweet potatoes in a 9-by-13-inch baking dish. Add sugar and bourbon and toss to combine; season with salt and pepper. Bake until sweet potatoes are tender and glazed, 1 to 1 1/2 hours, tossing every 30 minutes. Stir in butter before serving!