1. Add the Rice Chex cereal to a very large mixing bowl and set it aside. Crush the Butterfinger bars into small pieces and place the powdered sugar in a large zip-top bag or a container with a tight lid.

2. In a microwave-safe bowl, combine the chocolate chips, peanut butter, and butter. Microwave in 20-second intervals, stirring after each one, until the mixture is smooth and fully melted. Stir in the vanilla extract and salt.

3. Pour the melted chocolate mixture over the cereal. Gently fold until all the cereal is evenly coated.

4. Transfer the coated cereal to the bag or container with powdered sugar. Seal and shake until all the pieces are thoroughly coated.

5. Spread the puppy chow on a parchment-lined baking sheet or large tray and let it cool for 10 minutes.

6. Sprinkle the crushed Butterfinger pieces over the mix and toss gently so they distribute evenly.

7. Serve right away or store in an airtight container once fully cooled.