In a large ziplock bag, mix together the dry ingredients and shake to combine. Set aside.
In a large bowl, microwave the chocolate and peanut butter for 45-60 seconds, (30 seconds at a time, stirring every 30 seconds until the chocolate is melted.) Add the cereal to the bowl, and stir to coat the cereal in the peanut butter chocolate mixture.
Pour the chocolate peanut butter covered cereal into the ziplock with the dry ingredients, and shake until the cereal is evenly coated. Pour puppy chow onto a large baking pan lined with foil or parchment and let dry for at least 30 minutes. (Of course you can enjoy it immediately, but this time is just to allow the chocolate and peanut butter to completely set.) Store puppy chow in a sealed container, and store at room temperature for up to 7 days. Enjoy!