1. Preheat the oven to 325° and line a cookie sheet with parchment paper.
2. In a large bowl, combine the confectioners’ sugar with the cocoa powder, salt and nuts. Add the egg whites and vanilla to the dry mixture and combine until the dry ingredients are moist (do not over beat, as the batter can stiffen).
3. Drop spoonfuls of batter onto the baking sheet in evenly spaced mounds. Bake the cookies until the tops are slightly cracked and glossy, about 8 to 10 minutes.