3 egg whites (75 g), at room temperature
1 teaspoon pure vanilla extract
1/2 cup (40 g) unsweetened cocoa powder (natural or Dutch-processed)
2 cups (230 g) confectioners’ sugar
1/4 teaspoon kosher salt
6 ounces semi-sweet chocolate chips (can substitute a combination of chopped nuts and chips, by weight)
Preheat your oven to 325°F. Line large rimmed baking sheets with unbleached parchment paper and set them aside.
In a large bowl, place all but about 1 scant tablespoon of the egg whites and whisk vigorously by hand until the egg whites have begun to foam and thicken. Add the vanilla, and continue to whisk until the egg whites have nearly doubled in volume. Add the cocoa powder, and whisk until well-combined. The batter will be very thick, but just keep whipping and it will begin to smooth out. Add the confectioners’ sugar and salt, and the remaining egg whites, and whisk by hand until smooth and slowly pourable. The mixture will clump and thicken, but just keep whisking and it will become smooth again.
Add the chocolate chips to the cookie batter, and fold the chips into the batter using a wide spatula until the chips are evenly distributed throughout it.
Scoop the batter into about 12 or 24 portions, each 1 to 2 tablespoons, leaving about 2 inches between the cookies. The batter will spread, but slowly. Place the baking sheet in the center of the preheated oven and bake until the cookies are just set and beginning to crack on top, 12 to 14 minutes. They will puff in the oven, and then deflate as they cool. Remove from the oven and allow the cookies to cool completely on the baking sheets. For easy removal of the cookies from the parchment paper, place the baking sheet in the refrigerator for 5 minutes, and then peel away the parchment from the backs of the cookies. Leftovers can be stored in a sealed container in the freezer.
Originally published on the blog in 2013. Photos and video all new, method revised somewhat for clarification and consistency of results.