In a large mixing bowl, measure out the Rice Chex cereal and set aside.
In a microwave-safe bowl, combine the white chocolate chips and peanut butter. Microwave in 30-second intervals, stirring in between, until melted and smooth. This usually takes about 1-2 minutes.
Stir in the vanilla extract into the melted mixture until well combined.
Pour the melted mixture over the Rice Chex cereal and gently fold until all the cereal is evenly coated.
In a large resealable plastic bag, combine the powdered sugar and crushed freeze-dried strawberries.
Add the coated cereal to the bag, seal it tightly, and shake until all pieces are coated with the sugar and strawberry mixture.
Spread the puppy chow out on a baking sheet lined with parchment paper to cool and set for about 30 minutes.
Once cooled, serve immediately or store in an airtight container for up to a week.