If your ideal cookie has thin, crispy edges that enclose a thick, fudgy middle, then you should definitely be making these flourless chocolate cookies.
Line baking sheets with parchment paper, and spray with cooking spray.
Whisk together powdered sugar, Dutch cocoa, black cocoa, espresso powder, and salt.
Add egg whites and vanilla to dry ingredients, beat well.
Fold chocolate chips into the batter.
Scoop cookies onto prepared parchment and rest for 30 minutes.
Bake the cookies at 350°F until they’re shiny and cracked, 8 to 10 minutes. Cool for 1 minute on baking rack.