Preheat your oven to 350°F (175°C). Line your cookie sheets with parchment paper for easy cleanup.
In a medium bowl, whisk together the all-purpose flour, cocoa powder, baking soda, and sea salt. Set this mixture aside.
In a large mixing bowl, beat the unsalted butter, granulated sugar, and brown sugar together using an electric mixer until light and fluffy, about 2-3 minutes.
Add the eggs, one at a time, mixing well after each addition. Then, mix in the vanilla extract until fully incorporated.
Gradually add the dry ingredients to the wet mixture, mixing on low speed until just combined. Be careful not to overmix.
Gently fold in the milk chocolate chips, semisweet chocolate chips, and white chocolate chips using a spatula.
Using a cookie scoop or tablespoon, drop rounded balls of dough onto the prepared cookie sheets, leaving space between each cookie as they will spread while baking.
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 immediately press a few extra chocolate chips on top of each cookie for a beautiful finish. Sprinkle with a pinch of sea salt.
Allow the cookies to cool on the baking sheet for 5 minutes before transferring them to a cooling rack.