Prepare your workstation by lining a baking sheet with parchment paper.
In a microwave-safe bowl, combine the white chocolate chips and peanut butter. Microwave in 30-second intervals, stirring after each interval until the mixture is smooth and fully melted.
Remove the bowl from the microwave and stir in the vanilla extract and cherry-flavored gelatin until well combined.
In a large mixing bowl, measure out the rice Chex cereal. Pour the melted white chocolate and peanut butter mixture over the cereal and gently fold to coat the cereal evenly.
Once the cereal is thoroughly coated, carefully fold in the cherry pie filling, ensuring even distribution without smashing the cereal.
After combining, sprinkle the powdered sugar over the mixture, folding to coat all the cereal and cherries.
Spread the mixture onto the prepared baking sheet in an even layer. If using, sprinkle red sprinkles on top for decoration.
Allow the mixture to cool and set for about 10 minutes.
Once set, break the puppy chow into pieces. Store in a sealed container at room temperature or in the refrigerator for a firmer texture.