In a large microwavable bowl, microwave chocolate chips, peanut butter and butter for 1 minute. Stir mixture until smooth (microwave longer if needed). Stir in the vanilla extract. Add cereal and mix until coated. Allow to cool for 10 minutes.
Spoon cereal mixture into a large plastic bag. Add powdered sugar and shake the sealed bag until coated. Serve in bowls with chocolate candy pieces mixed in.
Enjoy!
Recipe by Sugar, Spice and Family Life at https://sugarspiceandfamilylife.com/2015/02/valentines-day-puppy-chow-recipe-aka-muddy-buddies.html