Instructions: Heat oven to 350 degrees. In an electric mixer, combine brown sugar, 1/3 cup granulated sugar, butter, and vanilla, and mix on medium-high speed until well combined. Add egg whites, and mix until combined.

In a small bowl, whisk together cocoa, flour, and salt. Add to sugar-and-butter mixture, and mix on medium until flour is completely incorporated. Turn this mixture out onto a piece of parchment or wax paper, and roll into a 1 3/4- by 8 1/2-inch log. Chill for at least 1 hour or overnight.

Remove paper, and slice log crosswise into 1/4-inch thick pieces. Place remaining 1 1/2 tablespoons granulated sugar in a small bowl, and dip each piece of dough in sugar, coating all sides; transfer to parchment-lined baking sheet 1 inch apart.

Bake about 14 minutes for chewy cookies; for crisp cookies, bake 2 to 3 minutes longer. Slide the paper and cookies onto a wire rack to cool completely.

Makes about 32 cookies.

If you would like to email yourself the recipe for later use, or share the recipe with your friends or family, enter the email addresses below and this recipe will be emailed to you and others as well.