In a bowl, combine the dry cake mix, vegetable oil, egg and vanilla; mix well. Stir in pecans. Refrigerate for 1 hour or until firm enough to handle.
Roll into 1-in. balls; dip top of each ball into toffee bits and set 2 in. apart on greased baking sheets. Bake at 350° for 10-12 minutes or until golden brown. Cool for 3 minutes before removing to wire racks.