Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper.

In a large mixing bowl, cream together the softened butter, dark brown sugar, and granulated sugar until light and fluffy.

Add the eggs one at a time, mixing well after each addition, then stir in the vanilla extract.

In a separate bowl, whisk together the flour, cocoa powder, baking soda, and salt.

Gradually add the dry ingredients to the wet mixture, mixing until just combined.

Fold in the dark chocolate chips until evenly distributed.

Using a cookie scoop or tablespoon, drop dough onto the prepared baking sheet, spacing them about 2 inches apart.

Bake for 10-12 minutes, or until the edges are set but the centers are still soft.

Let cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.