Measure the Rice Chex cereal into a very large mixing bowl and set aside.

In a medium microwave-safe bowl, combine the semi-sweet chocolate chips, creamy peanut butter, and butter. Microwave in 30-second intervals, stirring well between each interval, until completely smooth and melted. This usually takes about 60 to 90 seconds total. Stir in the vanilla extract.

Pour the warm chocolate-peanut butter mixture over the Rice Chex cereal. Using a large rubber spatula, gently fold and stir until every piece of cereal is evenly coated. Work quickly but carefully so the cereal does not break apart too much.

Transfer the coated cereal to a large zip-top gallon bag. Add the sifted powdered sugar, seal the bag, and shake vigorously for about 30 seconds until every piece is thoroughly coated in a thick, snowy layer of powdered sugar.

Spread the coated puppy chow out in an even layer on a large parchment-lined baking sheet. Let it cool and set at room temperature for at least 10 to 15 minutes.

Once cooled, transfer the puppy chow to a large serving bowl or keep it spread on the baking sheet. Add the mini pretzel twists and gently toss to distribute evenly throughout the mix.

In a small microwave-safe bowl, combine the white chocolate chips and coconut oil. Microwave in 30-second intervals, stirring between each, until fully melted and smooth. Add the orange gel food coloring, a few drops at a time, stirring until you reach a bright, vivid Halloween orange.

Using a spoon or a piping bag, drizzle the orange white chocolate over the top of the puppy chow mix in zigzag ribbons across the entire surface.

Immediately while the orange drizzle is still wet, scatter the candy eyes generously over the top so they set into the drizzle. Add the Halloween sprinkles across the surface.

Allow the orange drizzle to set completely, about 10 minutes at room temperature or 5 minutes in the refrigerator. Once set, break apart any large clusters and serve in a big bowl or divide into treat bags.