Heat oven to 350°F. Spray 13x9-inch (3-quart) glass baking dish with cooking spray. In small bowl, mix 1/4 cup of the melted butter and the crushed croutons; set aside.
In large bowl, mix remaining 1/4 cup melted butter and all remaining ingredients. Spoon into baking dish, spreading evenly.
Bake 40 minutes or until browned and bubbly around edges. Sprinkle crouton mixture over potato mixture; bake 10 to 15 minutes longer or until topping is browned.