Step 1: In a microwave-safe bowl, combine the white chocolate chips and unsalted butter. Microwave in 30-second intervals, stirring well after each, until smooth and fully melted.
Step 2: Add the softened cream cheese and vanilla extract to the melted chocolate mixture. Stir vigorously until completely smooth and well combined.
Step 3: Gently fold in the well-drained cherry pie filling until the mixture is evenly pink and cherry-flavored. If using cherry extract and food coloring, stir them in now.
Step 4: Place the Rice Chex cereal in a very large mixing bowl. Pour the cherry cheesecake mixture over the cereal. Gently fold and stir with a rubber spatula until all the cereal pieces are thoroughly coated.
Step 5: In a large (2-gallon) Ziploc bag or an extra-large airtight container, combine the powdered sugar and the optional graham cracker crumbs. Add the coated cereal to the bag or container.
Step 6: Seal the bag or container and shake vigorously for 2-3 minutes, or until every piece of cereal is completely coated with the powdered sugar mixture.
Step 7: Spread the Cherry Cheesecake Puppy Chow onto a baking sheet lined with parchment paper in a single layer. Allow it to cool and set for at least 30 minutes before serving.
Step 8: Store any leftovers in an airtight container at room temperature for up to 3-4 days, or refrigerate for up to a week for optimal freshness.