01 -
Line a rimmed sheet pan with parchment paper. Add the cereal to a very large mixing bowl and set the powdered sugar and salt inside a gallon-size zip-top bag.
02 -
Add the white chocolate, pink candy melts, peanut butter, and butter to a microwave-safe bowl. Microwave in 20 to 30 second bursts, stirring after each, until smooth. Stir in the vanilla.
03 -
Pour the melted coating over the cereal. Fold gently with a rubber spatula until the cereal is evenly coated, taking care not to crush the squares.
04 -
Transfer the coated cereal to the bag with powdered sugar and salt. Seal tightly and shake until the cereal pieces are coated and mostly dry.
05 -
Spread the puppy chow on the prepared pan in an even layer. Let it sit for 20 minutes, or until the coating feels set.
06 -
Break up any large clusters with your hands. Toss the coated cereal with pretzels, Valentine chocolate candies, and sprinkles before serving or packing.