In a large mixing bowl whisk together the flour, cocoa, baking soda, and salt until well combined.
Whip the butter until creamy and add in the sugars, beating till nice and fluffy. This will take 3-4 minutes with a handheld mixer.
Add the eggs one by one, beating well after each addition.
Then add the vanilla extract.
Add the dry ingredients, mixing until just combined and then fold in the chocolate chips and pistachios.
Ideally you should let the dough rest in the fridge for a couple of hours – or even better – overnight.
Whenever you’re ready to bake pull the dough out of the fridge to soften and preheat the oven to 350.
Line a baking sheet with parchment paper or a silpat. Drop the dough by rounded teaspoons onto the cookie sheet 1.5-2 inches apart and bake for 8-10 minutes.
Pull the cookies out as soon as the edges look crispier and the centers look set.