1. Heat oven to 350°F. Grease 13x9x2-inch baking pan.
2. Melt butter in medium saucepan over low heat. Add sugar and cocoa; stir to blend. Remove from heat. Stir in eggs. Stir together flour, salt and baking soda; stir into chocolate mixture. Stir in vanilla, chocolate chips and nuts. Spread in prepared pan.
3. Bake 30 to 35 minutes or until brownies begin to pull away from sides of pan and begin to crack slightly; do not underbake. Cool completely in pan on wire rack. Cut into bars. Makes about 24 brownies.