Borrowing from the classic dessert crème brûlée, this dish has a hard candy topping, a crisp contrast to the creamy sweet potatoes. Cooking time does not include cooking sweet potatoes.
Combine first 6 ingredients in a bowl. Spoon potato mixture into an 11 x 7-inch baking dish coated with cooking spray. Sprinkle 1/2 cup brown sugar evenly over top. Broil 2 minutes or until sugar melts. Let stand until melted sugar hardens (about 5 minutes).