Preheat the oven to 400°F. In a large bowl, whisk together the all-purpose flour, cake flour, cocoa powder, cornstarch, baking soda, baking powder and salt. Set aside.
Place the cold, cubed butter, white sugar and brown sugar into the bowl of a stand mixer and secure the paddle attachment. Cream until light and fluffy, 3-4 minutes.
Then add in the egg, egg yolk, red food coloring, vinegar and vanilla extract. (I like to turn the mixture off so the red food coloring doesn't splatter everywhere). Blend until mixed.
Gradually add in the dry ingredients followed by the chocolate chips until incorporated.
Measure out ~7 large cookies. (If sticky, use a little flour on hands to roll). Roll each cookie dough ball generously in the confectioners’ sugar. Place the cookies on an un-greased cookie sheet and gently press cookies down just a little to flatten them.
Bake the cookies for 10-12 minutes. Let cookies rest on the cookie sheet for 15 minutes and then using a spatula transfer them to a cooling rack. Enjoy!