In the bowl of your stand mixer fitted with the paddle attachment, mix together the butter, brown sugar, and granulated sugar on medium speed for 3 minutes. Add in the eggs, vanilla, salt, cocoa powder, corn starch, and baking soda. Mix for 1 minute until combined and smooth, scraping the sides and bottom of the bowl as necessary.

Turn the mixer to low and add in the flour until evenly mixed. Stir in the chocolate chips. Chill the dough for 15 minutes.

While the dough is chilling, preheat your oven to 400°F. Line a baking sheet with parchment paper and set aside.

Portion out 1/3 cup of the dough (or 4.5 ounces on a cooking scale). Place the dough in mounds onto your prepared baking sheet. Note – these are large cookies and I bake 4 cookies at a time. Bake for 9 – 11 minutes until cookies are set at the edges and on top. The middles will still be soft, this is ok.

Allow the cookies to cool for 3-4 minutes on the baking sheet and then transfer to a wire rack to cool completely.