Caramel Corn Snack Mix

Preheat oven to 300 degrees F (150 degrees C). In a large bowl, combine the popcorn, cereal, pretzels and pecans. In a saucepan over medium heat, combine the brown sugar, butter and corn syrup. Cook and stir until mixture comes to a boil. Reduce heat to medium low; cook without stirring for 5 minutes. Remove saucepan from heat and stir in vanilla and baking soda. Pour over popcorn mixture and toss until evenly coated. Bake at 300 degrees F (150 degrees F) for 30 minutes, stirring after 15 minutes. Transfer to large piece of parchment paper and cool completely. Break into chunks once cool.