In a large mixing bowl, whisk together the flours, cornstarch, baking soda, salt and chocolate chips.
In another large bowl, whisk together the melted butter and sugars until thick and glossy and slightly lighter in color, about 30 seconds or so.
Add the egg and yolk, one at a time, whisking after each addition. Add the heavy cream and vanilla and whisk again.
Add the dry ingredients to the wet and using a flexible spatula or wooden spoon mix just until combined. Do not over mix.
Scoop the dough with a 1/4 cup ice cream scoop or measuring cup onto a parchment-lined cookie sheet. Place in the freezer for 30 minutes, just to firm up and prevent spreading.
When ready to bake off the cookies, heat the oven to 375 F and place 12 balls of dough on to a second cookie sheet lined with parchment. Bake for 10 to 12 minutes or until the cookies are browned around the edges and are just this side of done in the middle.
Let cookies cool briefly before serving with tall glasses of icycold milk.