Begin by lining a 9x13-inch baking pan with parchment paper. This step ensures that your treats will come out easily and makes cleanup a breeze.
In a microwave-safe bowl, combine the semisweet chocolate chips, creamy peanut butter, and salted butter. Microwave in 30-second intervals, stirring in between until the mixture is completely melted and smooth.
Once melted, stir in the vanilla extract. This will elevate the flavor profile of your Muddy Buddy (Puppy Chow) Marshmallow Cereal Treats.
Add the miniature marshmallows to the melted chocolate mixture. Stir gently until all the marshmallows are well coated.
In a large mixing bowl, place the Rice Chex cereal. Pour the chocolate-marshmallow mixture over the cereal, folding gently until all the cereal is evenly coated.
Pour the coated mixture into the prepared baking pan. Use a spatula to press it down evenly, ensuring it’s compact.
Refrigerate the pan for about 30 minutes, or until the mixture is firm enough to cut into squares.
Once set, remove the treats from the pan and cut them into squares. Dust generously with powdered sugar for that classic Muddy Buddy look and added sweetness.