Preheat oven to 350 F (convection oven to 325 F)
Line 3 baking sheets with parchment paper
Whisk powered sugar, cocoa powder and ¼ salt in large bowl until uniform in color. Set aside.
Beat vanilla into egg whites until mixed.
Add egg mixture to dry ingredients. Mix with spoon until combined.
Fold in chocolate chips.
Using a 2T cookie dough scooper, scoop dough onto baking sheets leaving plenty of room for spreading. Do not overcrowd - 8/sheet works perfectly!
Sprinkle each cookie with Maldon Sea Salt Flakes.
Let rest for 30 minutes before baking.
Bake for approximately 15 minutes (8 if using a convection oven). Surface of cookies should crack a little.
Let cookies cool on sheets before removing to enjoy!
Serving Size 1