In saucepan over low heat and striring constantly, melst chocolate, peanut butter, and butter Stir until smooth Remove from heat and stir in vanilla Pour cereal into large bowl that has cover that can seal tightly Pour chocolate mixture over ceareal Stir cereal, coating with chocolate Add powdered sugar Cover and gently shake the mixture, turning the bowl over many times to cover all of the cereal with the powdered sugar as thurougholy as possible Store in bowl with cover on tight