1. Stir together flour, baking powder, baking soda and salt. Set aside.
2. In large mixing bowl beat butter, peanut butter, granulated sugar and brown sugar on medium speed of electruc mixer until light and fluffy. Add eggs and vanilla. Beat well. Stir in flour mixture and crushed cereal. Drop by rounded teaspoonfuls onto ungreased baking sheets. Using back of fork flatten each cookie in crisscross pattern.
3. Bake at 350° F about 14 minutes or until lightly browned. Remove immediately from baking sheets. Cool on wire racks.