Preheat your oven to 350°F (175°C) and line baking sheets with parchment paper.

In a stand mixer, cream together unsalted butter, light brown sugar, and granulated sugar until light and fluffy, about 3–4 minutes.

Mix in pure vanilla extract and the eggs, one at a time, scraping down the sides of the bowl as needed. Sift in the cocoa powder and mix until just combined.

In a separate bowl, whisk together flour, baking soda, and salt. Gradually add this mixture to the wet ingredients until just combined.

Gently fold in the semisweet chocolate chunks with a spatula, ensuring even distribution throughout the dough.

Scoop dough onto baking sheets, spacing about 2 inches apart. Lightly flatten each dough ball and bake for 15 minutes or until edges are set but centers are soft.

Allow cookies to cool on the baking sheets for about 5 minutes before transferring to a wire rack to cool completely.