Preheat oven to 325 degrees.

Grease and flour 9x13 pan.

In a large saucepan, combine the butter, sugar and water. Bring to a boil over medium-high heat. Reduce the heat to medium, add 1 cup of the chocolate chips and stir constantly until melted. Remove fro the heat.

While beating with an electri mixer set at the lowest speed, add the eggs to the saucepan, one at a time. Continue to beat until the mixture is well blended. Add the flour, salt and baking soda. Mix with a wooden spoon until smooth. Stir in the vanilla, walnuts and remaining chocolate chips. Pout the batter into the prepared pan. Bake in the oven for 45 minutes.

Let the browines cool completely on a rack. Prepare the frosting by creaming all of the ingredients together until smooth. Spread evenly over the brownies while they are still slightly warm.