Preheat the oven to 375 degrees F and line a large cookie sheet with parchment paper and set aside.
In a large bowl, whisk together the flour, cornstarch, baking soda, and salt and set aside.
In a separate large bowl or stand mixer fitted with a paddle attachment, cream together the shortening, light brown sugar, granulated sugar, and vanilla until light and fluffy.
Beat in the eggs one at a time, mixing after each addition just until incorporated.
Add in the dry ingredients in 3 separate additions, mixing between each one JUST until incorporated, do not overmix.
Fold in 1½ cups of chocolate chips and use a large ¼ cup-sized cookie scoop to portion out the dough onto the prepared baking sheet, leaving about 5 inches between cookies. No more than 8 should go on a half sheet-sized pan.
Top the balls of dough with some of the remaining chocolate chips and sprinkle with flaked salt and bake for 12 to 15 minutes, until the edges are lightly golden brown. For softer, chewier cookies, remove at 12 minutes and allow the cookies to cool on the pan for 5 minutes. For my solid cookies, cook for 14 to 15 minutes and only let the cookies cool on the pan for 1 to 2 minutes before transferring to a wire rack to cool. Bake off the rest of the dough.