Preheat oven to 250°F. Line a 12x16-inch baking sheet with parchment (if desired) and set aside.
Whisk the butter, brown sugar, and pumpkin pie spice together in a small bowl.
½ cup salted butter, ¼ cup brown sugar, 1 teaspoon pumpkin pie spice
In a separate large bowl, toss the Chex cereal, Caramel Bugles, and pretzel twists together, then drizzle the butter mix over top and toss again to combine.
4 cups Apple Cinnamon Chex cereal, 3 cups Bugles Sweet & Salty Caramel Corn Snacks, 3 cups mini pretzel twists
Toss the Chex mix out onto the prepared baking sheet in an even layer and bake for 1 hour, tossing every 15 minutes or until the Chex mix is a deep golden color.
Let it cool for at least 30 minutes or until fully cooled down then toss in the candy corn, pumpkins, and Reese's Pieces.
1 cup candy corn, 1 cup Brach's Mellowcreme Pumpkins, 1 cup Reese's Pieces
Toss to combine, then serve.