Preheat your oven to 350°F (175°C).

Cream together the softened butter, brown sugar, and granulated sugar in a mixing bowl for about 2-3 minutes.

Add the egg and vanilla extract to the bowl, mixing well until fully incorporated.

Combine the flour, dark cocoa powder, baking soda, and salt in another bowl, then gradually add to the wet ingredients.

Fold in the semi-sweet chocolate chips and dark chocolate chunks.

Scoop heaping tablespoons of dough onto a prepared baking sheet leaving space between each cookie.

Sprinkle a pinch of sea salt and additional chocolate chips on top.

Bake for 10-12 minutes or until edges are set.

Cool on the baking sheet for about 5 minutes before transferring to a wire rack.