Instructions

• Measure 8 cups Chex cereal into a very large bowl and set aside.
• Place 1 cup semi-sweet chocolate chips, 1/2 cup creamy peanut butter, and 1/4 cup salted butter in a microwave-safe bowl. Microwave on high in 30-second intervals, stirring thoroughly after each interval, until the mixture is completely smooth and melted.
• Stir 1 teaspoon vanilla extract into the melted chocolate mixture, if using.
• Pour the melted chocolate mixture over the Chex cereal. Gently fold and stir with a spatula until the cereal is evenly coated.
• Put 1 cup of the powdered sugar into the bottom of a large zip-top bag. Transfer the coated cereal into the bag. Add the remaining 1/2 cup powdered sugar (for a total of 1 1/2 cups), seal the bag, and shake and massage until the cereal pieces are evenly coated with powdered sugar. (If the bag is too small, do this in two batches.)
• Spread the coated puppy chow onto a parchment paper–lined baking sheet and separate any large clumps so pieces are mostly individual. If you want it sweeter, dust with additional powdered sugar to taste (optional).
• Let the puppy chow cool completely to room temperature. Store in airtight containers or bags for up to 10 days at room temperature or up to 2 weeks in the refrigerator.