Chocolate Walnut Cookies

• 2-3/4 cups :walnut halves (9 ounces), toasted then chopped
• 3 cups :confectioners' sugar
• 1/2 cup plus 3 tablespoons :unsweetened Dutch-process cocoa powder
• 1/4 teaspoon :salt
• 4 large egg whites, :at room temperature
• 1 tablespoon :pure vanilla extract

Preparation

1. Preheat the oven to 350.
2. In a large bowl, whisk together the confectioners' sugar with the cocoa powder and salt. Whisk in the chopped walnuts.
3. Add the egg whites and vanilla extract and beat just until the batter is moistened (be careful not to overbeat or it will stiffen).
4. Spoon the batter onto the baking sheets in 12 evenly spaced mounds.
5. Bake the cookies for about 20 minutes, until the tops of the cookies are glossy and lightly cracked and feel firm to the touch; shift the pans from front to back and top to bottom halfway through.
6. Slide the parchment paper (with the cookies) onto 2 wire racks to cool completely before serving.