In the bowl of a stand mixer or in a large bowl and using an electric hand mixer, cream together butter, cream cheese, and sugars.
Add egg and vanilla extract and beat again until well-combined.
In a separate, medium-sized bowl, whisk together flour, cornstarch, baking soda, and salt.
With mixer on low-speed, gradually add flour mixture to butter mixture. Be sure to scrape the sides and bottom of the bowl with a spatula to ensure all ingredients are thoroughly combined.
Add broken Oreos and mini chocolate chips and use a spatula to stir until well-incorporated into the batter.
Cover bowl with plastic wrap and chill in the refrigerator for at least 30 minutes.
When dough has chilled and you are almost ready to bake, preheat oven to 350F (175C). Prepare cookie sheets by lining with parchment paper.
When oven is preheated, remove cookie dough from fridge and drop cookie dough by heaping 1 ½ Tablespoon-sized scoops onto baking sheet, spacing cookies at least 2” apart.
Transfer to 350F (175C) oven and bake for 10-12 minutes or until cookies are just beginning to turn golden brown around the edges. Allow cookies to cool completely on baking sheet before enjoying.
