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

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

Beat in the eggs one at a time, then stir in the vanilla extract.

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

Fold in the semi-sweet, white, and milk chocolate chips until evenly distributed.

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

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

Remove from the oven and let the cookies cool on the baking sheets for 5 minutes before transferring them to wire racks to cool completely.