Step 1: Measure out 9 cups of Chex cereal and set aside in a very large mixing bowl.
Step 2: Pulverize the freeze-dried strawberries into a fine powder using a food processor or by crushing them in a zip-top bag with a rolling pin. Set aside.
Step 3: In a microwave-safe bowl, combine the white chocolate chips or candy melts with the butter or coconut oil.
Step 4: Microwave on medium power (50%) for 30-second intervals, stirring thoroughly after each interval, until the white chocolate is completely melted and smooth. This usually takes 1.5-2 minutes total. Be careful not to overheat.
Step 5: Pour the melted white chocolate mixture over the Chex cereal in the large mixing bowl. Gently fold with a rubber spatula until all the cereal pieces are evenly coated. Work quickly before the chocolate sets.
Step 6: In a very large 2-gallon zip-top bag or a large paper bag, combine the powdered sugar and the freeze-dried strawberry powder. Shake the bag gently to mix them thoroughly.
Step 7: Carefully transfer the white chocolate-coated cereal into the bag with the powdered sugar and strawberry mixture. Seal the bag, leaving plenty of air inside.
Step 8: Gently shake and tumble the bag for 2-3 minutes, ensuring every piece of cereal is completely coated with the pink powdered sugar mixture.
Step 9: Spread the coated puppy chow in a single layer on a parchment-lined baking sheet or wax paper. Allow it to cool completely at room temperature for 15-30 minutes, or refrigerate for 10-15 minutes, until the coating is set.
Step 10: Once cooled, break up any large clumps. Your easy strawberry shortcake puppy chow is now ready to serve and enjoy!