1Line cookie sheet with waxed paper. In medium microwavable bowl, microwave chocolate chips uncovered on High about 2 minutes, stirring once, until melted and chips can be stirred smooth. Stir in peanuts and peanut butter.
2On cookie sheet, spread chocolate mixture to 1/4-inch thickness. Sprinkle chopped candy bars over top; press in lightly. Refrigerate 30 minutes. Break into 2-inch pieces.