How to Make It
Preheat the oven to 350°. Line 2 cookie sheets with parchment paper. In a food processor, pulse the pecans until finely ground. In a small bowl, combine the pecans and cocoa.
In a large mixer, beat the egg whites at high speed until foamy. Add the salt and beat until stiff. Lower the speed to medium and add the confectioners; sugar 1/2 cup at a time. Scrape down the bowl with a large rubber spatula, and beat at high speed for 30 seconds longer. Using the spatula, fold in the nut mixture.
Spoon the batter onto the prepared cookie sheets in 1/2-tablespoon mounds. Bake for 10 minutes, or until the tops crack slightly (the cookies may appear a little moist). Slide the parchment paper onto a rack and let the cookies cool completely. Remove the cookies from the paper and serve.