Preheat your oven to 350 degrees F. Spray a 9" x 13" baking dish with nonstick spray. Set aside.
In a medium size mixing bowl, sift together the flour, cocoa powder, and salt. Set aside.
In a medium size saucepan, melt the butter and the bittersweet chocolate chips until smooth. Remove from the heat and allow to cool for about 5 minutes.
Add the brown sugar to the butter and stir until smooth.
Add the eggs, one at a time, stirring well between each addition.
Stir in the vanilla.
Add the flour mixture and stir until no streaks of flour remain.
Fold in 3/4 cup of the semi-sweet chocolate chips.
Pour the batter into the prepared pan. Sprinkle remaining semi-sweet chocolate chips on top.
Bake the brownies for 25 to 30 minutes.
Remove the pan from the oven and allow the brownies to cool for about 15 to 20 minutes before serving.