Preheat oven to 300 degrees F. Using cooking spray or shortening, grease a 15x10x1-inch pan.
Toss corn snacks, peanuts, and cereals in a large bowl and set aside. In a separate bowl, whisk egg whites, orange juice, sugar, and cinnamon until foamy. Pour this mixture over the cereal mixture and coat evenly. Spread in pan.
Bake 45 to 50 minutes, stirring every 15 minutes, until light brown and crisp. Allow to cool completely and store in an airtight container.