Preheat oven to 400 degrees F. Line two large baking sheet with parchment paper or nonstick foil.

Stir powdered sugar, cocoa powder, and salt together in a bowl

Place egg whites in very clean metal or glass mixing bowl. Add the sugar mixture and stir with a rubber scraper, scraping sides of bowl, until ingredients are well mixed and batter is smooth and thick.

With a handheld electric mixer, beat for exactly two minutes. Mixture will thicken slightly, but it will not be light and fluffy like meringue. Stir in pecans.

Working quickly, drop the batter onto the baking sheets by rounded tablespoons, spacing about 2 ½ inches apart. Bake the cookies on the center and lower rack for 10-12 minutes or until dry, puffed and cracked on the surface.

Let the cookies cool for about 5 minutes on the parchment paper. Carefully remove cookies and let cool completely on a wire rack.

Store cookies in an airtight container or freeze.