1 1/2 c. Corn Chex
1 1/2 c. Rice Chex
1 1/2 c. Wheat Chex
4 c. air-popped popcorn
1/4 c. (1/2 stick) butter
6 tbsp. brown sugar
2 tbsp. light corn syrup
1/4 tsp. vanilla extract

Preheat oven to 250 degrees. In open roasting pan combine cereals and popcorn; set aside. In medium saucepan combine butter, sugar, corn syrup and vanilla. Cook over medium heat 5 minutes or until mixture is boiling, stirring frequently. Pour hot mixture over cereal mixture, stirring until all pieces are evenly coated.

Bake 45 minutes, stirring every 15 minutes. Spread on waxed paper to cool, stirring occasionally. Store in airtight container.