Start by preheating your oven to 350 F and lining your cookie sheets with parchment paper.
In a medium bowl, whisk together the sugar, cocoa powder, and salt.
Add in the egg whites and vanilla extract and mix until a thick brownie like batter forms.
Fold in the chocolate chips.
Using a cookie scoop, drop spoons of dough onto the cookie sheet about 2 inches apart. The cookies spread as they bake.
Bake for 12-14 minutes, or until the tops begin to crack.
Once you take them out of the oven, make sure they completely cool before removing from the parchment. If they are still warm, they will stick.
In a small bowl, warm the Nutella in the microwave for a few seconds until smooth enough to drizzle.
Drizzle the Nutella on top of each cookie, then sprinkle on the sea salt and pistachios.