Preheat the oven to 350°F. Line a baking sheet with parchment paper.
In a large bowl, cream together the softened butter, granulated sugar, and brown sugar until light and fluffy. Add the eggs and vanilla extract. Mix until fully combined.
In a separate bowl, whisk together flour, cocoa powder, baking soda, and ½ teaspoon salt. Gradually add the dry ingredients to the wet ingredients and mix until a thick dough forms.
Fold in the semi-sweet chocolate chips and white chocolate chips. Refrigerate for 30 minutes. Remove the dough from the refrigerator for 10 minutes before baking.
Scoop dough onto the prepared baking sheet using a cookie scoop or tablespoon. Sprinkle the top of each cookie with a pinch of sea salt. Space them a couple of inches apart. Cookies will spread slightly when baking.
Bake for 9–10 minutes, or until the edges are set and centers look slightly underbaked.
Let cookies cool on the pan for 5 minutes before transferring to a wire rack.