Chex Muddy Buddies

In a large bowl, measure cereal, and set aside. Melt chocolate chips, peanut butter, and butter over low heat. You can also do it in the microwave. Stir until smooth then add vanilla. Pour over the cereal. Stir everything gently until completely covered. Pour into a 2-gallon plastic container along with powdered sugar. Shake until everything is evenly coated. Spread on wax paper to cool and serve.