Preheat oven to 375 degrees F. Line baking sheets with parchment paper or silicone liner.
In a large mixing bowl, beat the butter and sugars until creamy. Mix in the eggs, one at a time, then the vanilla. In a separate medium bowl, whisk together the flour, cocoa powder, baking soda and salt. Slowly add the dry ingredients to the wet ingredients. Blend until combined, then stir in the chocolate chips.
Use a 4-tablespoon sized cookie scoop (leveling off the dough in the scoop to ensure equal portions) and drop dough balls onto cookie sheets (8 cookies per sheet). Bake for 10-11 minutes, rotating pans halfway through the baking time. Remove from the oven and allow to cool on the cookie sheet for 5 minutes before transferring to a wire rack to cool completely.