In a medium bowl sift together the flour, cocoa, baking soda and salt.
In a stand mixer with the paddle attachment or a large bowl and electric beater beat on medium speed the sugars and butter until light and fluffy, approximately 2-3 minutes. Add the vanilla and egg and beat to combine.
Add the dry ingredients and mix on low to almost combined. Add the chocolate chips and mix a few times to combine, or stir in with a spatula or wooden spoon. Don’t over mix or you will make a tough hard cookie. Cover the bowl and refrigerate for 1 hour.
Roll the cookie dough into 1 – 1 1/2 inch balls or drop with a tablespoon or medium cookie scoop onto parchment paper lined baking sheets, about 2 inches apart. Chill the cookie dough balls while the oven is pre-heating, approximately 15-20 minutes.
Pre-heat oven to 350F (180C).
Bake for approximately 10-12 minutes. Let cool on the baking sheet for 5-10 minutes then move to a cooling rack to cool completely before serving.
Notes
If you like you can top the still hot cookies with a few extra chocolate chips!Because the cookies are so dark the best way to tell when they are done is by looking and gently touching the edges, if the edges are set, the cookies are done.Store the cookies in an airtight container at room temperature. They should last for 4-5 days. Raw cookie dough will last up to 3 days in the fridge, be sure to wrap it well in plastic wrap and place in an airtight container or bag.Freeze the completely cooled cookies in a freezer safe bag or container. They will keep for up to 3 months. You can also freeze the cookie dough balls.Freeze them first on a baking sheet until firm then move to a freezer bag or container. The cookie dough will last for up to 2 months. Bake right from frozen, they will need a bit longer to bake.