In a large bowl, combine the cereals, peanuts and pretzels. In a small bowl, combine the remaining ingredients; pour over cereal mixture and toss to coat.
Transfer to two 15-in. x 10-in. x 1-in. baking pans coated with cooking spray. Bake at 250° for 1 hour, stirring every 15 minutes. Cool completely on wire racks. Store in an airtight container. Yield: 3-1/2 quarts.