Heat oven to 350°F. Line a 15 x 10-inch jelly-roll pan with foil. Coat foil with cooking spray.
In large bowl, combine coconut, walnuts, brown sugar, salt and melted butter until well mixed.
In medium-size saucepan, melt butter over medium heat. Stir in sugar and cocoa. Remove from heat. With wooden spoon, beat in eggs, one at a time. Stir in vanilla, then flour and salt. Pour brownie batter into prepared pan. Sprinkle topping evenly over batter.
Bake in 350°F until golden and brownie is just set in center, 25 to 30 minutes. Let cool in pan on rack. Grab edges of foil to remove brownies from pan. Cut into 48 squares. With spatula, remove brownies from foil.