Preheat the oven to 350°F (175°C). Line two baking sheets with parchment paper.
In a large bowl, cream together the softened butter, granulated sugar, and light brown sugar until light and fluffy, about 3-4 minutes.
Beat in the eggs one at a time, then stir in the vanilla extract until well combined.
In a separate bowl, whisk together the all-purpose flour, unsweetened cocoa powder, baking soda, and salt.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined.
Fold in the semisweet chocolate chips evenly throughout the dough.
Using a tablespoon or cookie scoop, drop rounded spoonfuls of dough onto the prepared baking sheets, spacing them about 2 inches apart.
Bake in the preheated oven for 10 to 12 minutes, or until the edges are set but the centers still look slightly soft.
Allow the cookies to cool on the baking sheets for 5 minutes before transferring them to a wire rack to cool completely.