In a medium size bowl, whisk together the flours, cornstarch, baking soda, and salt. Set aside.
In the bowl of a stand mixer fitted with a paddle attachment, or in a bowl with an electric hand mixer, beat the sugars and butter on medium-high speed until light and paler in color, about 2-3 minutes. You may need to scrape down the bowl after a minute and keep beating to ensure everything is evenly incorporated.
Add in the vanilla and egg yolks and beat until fully combined.
Then, add in the dry ingredients and mix on low speed until just combined.
Lastly, fold in the chocolate.
With a 2 tablespoon cookie scoop, place 12 balls of cookie dough on one baking sheet, top each with more chopped chocolate, and freeze for 15 minutes.
While the dough is in the freezer, preheat the oven to 325 degrees F. Place the cookie dough 2 inches apart on a parchment lined baking sheet and bake for 15-16 minutes.