Preheat oven to 350° F. Line a baking sheet pan with a silicone baking mat or parchment paper.
In a mixing bowl with an electric hand mixer or bowl of a stand mixer fitted with a paddle attachment, cream together butter and sugars on medium speed until light and fluffy.
Add in eggs and vanilla extract and continue to mix until well combined.
Add in flour, cocoa powder, baking soda, and salt. Mix until the dry ingredients are fully incorporated. The dough will be very stiff.
Using a spatula, fold in the semisweet and dark chocolate chips until well dispersed throughout the cookie dough.
Divide into 24 cookies using a cookie scoop or a kitchen scale. If using a kitchen scale, you will want to measure approximately 2 ounces.
Chill the cookie dough balls for at least 30 minutes.
Place the cookie dough balls onto your prepared baking pans. Bake 6 to 8 cookies on the pan at a time and allow for space in between the cookies.
Bake in the oven for 12-14 minutes.
Remove from the oven and allow the cookies to cool on the baking trays for 5 minutes.
Remove the cookies from the baking tray and transfer to a wire rack to cool to room temperature.