In a small bowl, mix together flour and baking soda. In a small saucepan, mix together sugar, butter and water and bring to boil over medium heat. As soon as mixture starts to boil remove from heat. Stir in 1 cup chocolate morsels and vanilla until chocolate is melted and mixture is smooth. Transfer to medium bowl and cool completely. Stir in eggs one at a time, beating well, and stir in flour mixture until smooth. Stir in remaining chocolate morsels and nuts; pour into greased 9-inch square baking pan and bake at 325ºF for 30-35 min. or until toothpick inserted in centre comes out clean. Place pan on wire rack and allow to cool completely before cutting into 16 brownies.