Preheat your oven to 400 degrees. In a big mixing bowl, blend together cold, cubed butter, brown sugar, and sugar until it’s light and fluffy. This step is crucial—it makes the butter create a creamy texture with the sugars.
Add eggs and vanilla, and mix for an extra minute.
Fold in flour, baking soda, cornstarch, and salt—just until everything’s combined. Now, add in the good stuff: semi-sweet chocolate chips, white chocolate chips, and chopped Oreo cookies.
Roll the dough into light balls. You can choose between 4-ounce, 5-ounce, or 6-ounce cookie dough balls. Bake them on a light-colored baking sheet for 9-10 minutes. Pro tip: If your baking sheet is dark, the bottoms might burn before the insides are fully baked, so be cautious. Whatever you do, don’t overbake!
Let the cookies cool for 10 minutes before taking them off the baking pan. For a gourmet touch, place a few Oreo cookies on top of the cookies as soon as they come out of the oven.