In a large bowl, beat peanut butter and butter until blended; gradually beat in confectioners' sugar until smooth. Stir in cereal. Shape into 1-in. balls. Refrigerate until chilled., In a microwave, melt chocolate chips and 1/4 cup shortening; stir until smooth. Dip balls into chocolate; allow excess to drip off. Place on a waxed paper-lined pan. Let stand until set. , In a microwave, melt white baking chips and remaining shortening. Stir until smooth. Drizzle over candies. Refrigerate until set.