Preheat oven to 425°F.Spray an 11 x 7-inch baking dish with cooking spray.In a large bowl, combine potatoes, butter, salt, garlic powder and fresh cracked pepper.Arrange half of the potato slices in the baking dish; top with 1/4 cup cheese. Add the remaining potatoes.In a small saucepan, bring milk, thyme, bay leaf and nutmeg to a boil; pour over potatoes.Top with remaining cheese and bake uncovered, for 45 – 50 minutes, or until potatoes are tender.