Preheat oven to 350. Spray pam a 13 by 9 inch pan. In a small bowl, combine flour, baking soda, and salt. In a small saucepan, melt butter and sugar with water; stir until the sugar dissolves. Add 2 cups chips and stir till their melted. remove from heat and stir in vanilla.
In a large bowl, beat the eggs. Add chocolate mix, and flour mix, mix until just combined. stir in remaining chips. Bake 25-30 minutes.