1. Heat oven to 325°F. Grease 13x9x2-inch pan.
2. Beat butter, brown sugar and granulated sugar until well blended. Add eggs, milk and vanilla; beat well. Stir together flour, baking soda and salt; blend into butter mixture. Stir in chocolate pieces and nuts, if desired. Spread in prepared pan.
3. Bake 30 to 35 minutes or until dark golden brown. Cool completely in pan on wire rack. Cut into bars. Makes 24 to 36 bars.