Combine flour, baking soda, and salt in small bowl and set aside. With an electric mixer, beat sugar and butter until creamy. Beat in eggs and vanilla extract until combined.
Gradually beat in flour mixture. Fold in Butterfinger candy pieces with a wooden spoon or spatula. Drop by slightly rounded tablespoonfuls onto silpat covered baking sheet.
Bake at 375 degrees for 10-12 minutes or until lightly browned. Cool on baking sheets for 5 minutes, then transfer to a wire rack to cool completely.