In a large mixing bowl with an electric hand mixer or bowl of a stand mixer with an paddle attachment, cream butter and sugars together until light and fluffy.
Add in eggs and vanilla extract and beat again until combined.
In a medium mixing bowl whisk together flour, cornstarch, baking powder, and baking soda.
Add dry ingredients to wet ingredients and mix just until combined, scrapping the sides of the bowl with a rubber spatula.
Roughly chop 5 Oreos and add them to the cookie dough along with the chocolate chips.
Spoon 1/4 cup of cookie dough and divide the large dough ball in half. Add an Oreo in the middle of the two dough balls then gently smash them back together and roll into a large dough ball. Repeat until you've made 15 dough balls.
Place the dough balls on a baking sheet or large plate, cover with plastic wrap, and place in the refrigerator to chill for 30 minutes.
Preheat oven to 350 degrees and place cookie dough balls on a parchment paper lined baking sheet, leaving 2 inches apart. There should be 6 cookies per each sheet. Bake for 11-12 minutes and then let cool for a few minutes before transferring to a cooling rack. If you want your cookies on the gooey and doughier side, bake for 10 minutes. Enjoy!