Prepare your workspace by lining a baking sheet with parchment paper and gathering all equipment and ingredients.
In a microwave-safe bowl, combine the white chocolate chips and unsalted butter. Microwave on high in 30-second intervals, stirring after each until the mixture is smoothly melted and combined.
Stir in the lemonade drink mix and salt until well incorporated into the melted chocolate mixture.
In a large mixing bowl, add the Rice Chex cereal. Pour the melted mixture over the cereal and gently fold until all pieces are coated.
Once coated, transfer the mixture to a large zip-top bag. Add the powdered sugar and lemon zest. Seal the bag and shake vigorously until the cereal is evenly coated with the powdered sugar and zest.
Spread the coated puppy chow onto the prepared baking sheet and let it cool for about 10 minutes.
Once cooled, break into pieces and serve immediately or store in an airtight container.
For an extra zesty flavor, you can add a few drops of lemon extract to the melted mixture.