
Double chocolate just means sifting cocoa powder in with the cookies and then adding the chocolate chips as well. I added extra peanut butter, and since I had no peanuts lying around subbed pecans. Still really good.
I got the recipe from Food 52, and I have to say they have some of my favourite cookie recipes- check it out. You can find the recipe here.
Final tip- this recipe makes slightly more dough than needed for two pans. Freeze it. Then eat it frozen right out of the freezer and realize its even better that way.