In a large bowl, measure out the Rice Chex cereal and set aside.

In a microwave-safe bowl, combine chocolate chips and peanut butter. Heat in the microwave in 30-second increments until melted and smooth.

Pour the melted mixture over the Rice Chex and gently stir to coat.

Allow the coated cereal to cool slightly, then add the Lucky Charms marshmallows and mix well.

Place the powdered sugar in a large resealable bag, add the coated cereal mixture, and shake until well coated.

If using candy coating, melt it and drizzle over the puppy chow, mixing well.

Spread on a baking sheet to cool completely before serving.