In a microwave, melt 3 oz. white candy coating at 70% power for 1 minute; stir. Microwave at additional 10- to 20-second intervals, stirring until smooth. Stir in peanut butter until smooth. Add the confectioners' sugar, vanilla and cereal. Chill for 2-3 hours or until easy to handle.
Shape into 1-in. balls; set aside. In a microwave, melt chocolate and shortening; stir until smooth. Dip balls in chocolate; allow excess to drip off. Place on a wire rack over waxed paper; let stand until set, about 15 minutes.
Melt remaining coating; cool for 5 minutes. Drizzle over truffles. Chill for 5-10 minutes or until set. Cover and store in the refrigerator.