PREHEAT oven to 375° F.
COMBINE flour, baking soda and salt in small bowl. Beat sugar and butter in large mixer bowl until creamy. Beat in egg; gradually beat in flour mixture. Stir in Butterfinger pieces. Drop by slightly rounded tablespoon onto ungreased baking sheets.
BAKE for 10 to 12 minutes or until lightly browned. Cool on baking sheets for 2 minutes; remove to wire racks to cool completely.