In large electric mixer bowl, beat peanut butter, margarine and sugar on medium speed until thoroughly combined. Add KELLOGG'S® RICE KRISPIES® cereal, mixing thoroughly. Portion mixture, using rounded teaspoon. Shape into balls. Place each ball in paper cup. Refrigerate.
Melt chocolate morsels and shortening in small saucepan, over low heat, stirring constantly. Spoon 1 teaspoon melted chocolate over each peanut butter ball. Refrigerate until firm. Store in airtight container in refrigerator.