Step 1

Preheat oven to 320°F (160°C). Line a large cookie sheet with parchment paper or a silicone baking mat.

Step 2

Add cocoa and powdered sugar to a large mixing bowl. Stir with a whisk until evenly combined.

Step 3

Add in egg whites. Whisk until batter is smooth and no pockets of powdered sugar remain. It may seem like you don't have enough liquid at first but just keep stirring and as the egg whites break down and get absorbed, you will have enough moisture. The batter should be very thick and sticky and if you scoop some of it out, it should barely move. If your batter appears to be a little runny, add in a little more cocoa powder (about 1/2 to 1 tbsp more).

Step 4

Using a 2 tsp cookie scoop, scoop cookie dough and release onto prepared cookie sheet, spaced 2 inches apart. Repeat with remaining batter.

Step 5

Bake cookies about 15-18 minutes or until done. (Mine took around 16-17 minutes). When cookies are done, they will puff up and have a shiny surface. Let cookies cool on cookie sheet and set fully before removing. Store uneaten cookies in an airtight container at room temperature.