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

In a large bowl, cream butter, brown sugar, and granulated sugar until light and fluffy.

Add eggs and vanilla extract, mixing until fully combined.

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

Gradually add dry ingredients to the wet mixture until a thick dough forms.

Fold in chocolate chips or chunks evenly.

Cover and chill dough for 30 minutes to create thicker cookies.

Scoop dough onto baking sheets, spacing cookies 2–3 inches apart.

Bake for 10–12 minutes, until edges are set and centers are soft.

Cool on the baking sheet for 5 minutes, then transfer to a wire rack.