Using a stand mixer fitted with the paddle attachment or a hand mixer, cream the butter and brown sugar on high for 1-2 minutes. Scrape down the bowl once complete.
Add in milk, vanilla extract and salt. Mix until combined. Scrape down the bowl once complete.
Add flour to a microwave-safe bowl and heat on high in the microwave for 90 seconds, stopping every 15-20 seconds to stir the flour. Set aside to cool for 2-3 minutes.
Let the flour cool, then add it to wet ingredients in 3-4 portions, mixing well after each addition.
Use a large spoon to mix in the chocolate chips.
Form 1-2 teaspoon-sized cookie dough balls and place them on top of the Oreo crust. Press them down slightly to flatten them (see photo above). Set aside.