In a large saucepan, stir together brown sugar, corn syrup, and butter.
¾ cup brown sugar, ½ cup light corn syrup, 3 tablespoons butter
Heat over medium heat and bring to a boil, stirring regularly.
Boil for 6 minutes, stirring regularly.
Remove from heat.
Stir in the vanilla and baking soda until well-combined.
1 ½ teaspoons vanilla extract, ¼ teaspoon baking soda
Pour the caramel mixture over the popcorn mixture.
Bake for 15 minutes.
Stir.
Continue baking for an additional 45 minutes, stirring every 15 minutes.
Let cool completely.
Add candy mix before serving.
11 ounce package Autumn Candy Mix
Notes
Cereal: Feel free to adjust the amount of cereal to your liking (i.e. 3 cups of Chex and 1 cup of Cheerios).
Peanuts: You can use an additional cup of cereal in place of the peanuts. Or you can substitute 1 cup of pretzels for the peanuts. Also, I like to use salted peanuts for a salty/sweet combo.
Candy: Autumn candy mix is a mix of candy corns and candy pumpkins. You can use a mix of all candy corn or all pumpkins if you prefer.