Summarize this article in one sentence.
Take your prepared pan, and press the half of the cookie dough into the bottom. Make sure to place the dough in as even a layer as possible. You can save the rest of the cookie dough for another use because you don't want to make the cookie layer too thick. If stored in an airtight container, it will last in the fridge for up to 2 days and in the freezer for up to 6 months. With the chocolate chip cookie dough placed in the bottom of the pan, set a layer of Oreo® cookies on top of it. Lay as many cookies as necessary to cover the dough, but don't overlap them. Gently press the Oreo® cookies into the chocolate chip cookie dough to keep them in place. It usually takes approximately 16 Oreo® cookies to cover the cookie dough layer. With the two cookie layers in place, add all of the brownie batter on top of the pan. Use a spatula to spread the batter over the cookie layers to ensure that it's even. Place the pan in the preheated oven, and bake for 30 to 35 minutes. To determine if the brownies are done, stick a knife in the center of the pan. If it comes out mostly clean, they're baked through. If you stick a knife in the center of the brownies and it comes out covered with batter or crumbs, leave the brownies in the oven and check again in 5 minutes. While the brownies are particularly delicious when they're still warm, you should allow them to cool for at least 10 minutes before cutting them. That will make it easier to slice them into 16 even bars with a sharp knife. If you want to serve the brownies warm, you can, but be aware that they'll be messier when you cut them.
Press the cookie dough into the bottom of the pan. Place a layer of Oreo® cookies on top of the cookie dough. Pour the brownie batter over the Oreo® cookie layer. Bake the brownies for 30 to 35 minutes. Cool and cut the brownies into bars.