In a large bowl, cream butter and sugar. Add egg; beat well. Combine the flour, cinnamon and salt; add to creamed mixture and beat until smooth. Stir in pecans. Spread into a greased 8-in. square baking pan.
Bake at 350° for 35-40 minutes or until a toothpick inserted in the center comes out clean. Cut into small bars while warm; roll in confectioners' sugar.