PREPARATION:
- Preheat oven to 350°F. Place flour, baking powder, baking soda and salt in small bowl; stir to combine.
- Beat butter, granulated sugar and brown sugar in large bowl with electric mixer at medium speed until light and fluffy, scraping down side of bowl once. Beat in peanut butter, egg and vanilla, scraping down side of bowl once. Gradually stir in flour mixture, blending well.
- Shape heaping tablespoonfuls of dough into 1-1/2-inch balls. Place balls 2 inches apart on ungreased cookie sheets. (If dough is too soft to roll into balls, refrigerate 30 minutes.) Dip table fork into granulated sugar; press criss-cross fashion onto each ball, flattening to 1/2-inch thickness. Bake 12 minutes or until set. Let cookies stand on cookie sheets 2 minutes. Remove cookies to wire rack; cool completely.
- Melt semisweet chocolate chips and 1-1/2 teaspoons shortening in top of double boiler over hot, not boiling, water. Dip one end of each cookie one third the way up; place on waxed paper. Let stand until chocolate is set, about 30 minutes.
- Melt milk chocolate chips with remaining 1-1/2 teaspoons shortening in top of double boiler over hot, not boiling, water. Dip plain end of each cookie one third the way up; place on waxed paper. Let stand until chocolate is set, about 30 minutes.
- Store cookies between sheets of waxed paper at cool room temperature.