Preheat oven to 200°.
Combine the first 6 ingredients in a large bowl; set aside. Melt the butter in a small saucepan over medium heat. Add sugar and remaining ingredients, stirring with a whisk. Pour butter mixture over cereal mixture, tossing gently to coat. Spread the mixture onto a jelly roll pan coated with cooking spray. Bake at 200° for 45 minutes. Cool completely before serving.