Preheat oven to 350 degrees. Cover cookie sheets with parchment paper. In a large bowl whisk cocoa powder, salt and powdered sugar together. Add vanilla and slowly whisk in egg whites. Batter will be thick almost like a brownie mix. Gently fold in all chocolate chips. Spoon 1 tablespoon of cookie batter onto cookie sheet. Be sure to leave enough room between each cookie for spreading. Bake for 10-11 minutes. Let cool and gently remove from parchment paper. Enjoy!