Now, let’s get into the fun part—making these beauties! Trust me, it’s easier than it looks, and you’ll have them ready in no time.

1. Preheat your oven and prepare your pan:
   • Preheat your oven to 350°F (175°C).
   • Line a 9×13-inch baking pan with parchment paper or aluminum foil, leaving an overhang so you can easily lift the brownies out later. This makes clean-up super easy too!
2. Make the cookie dough layer:
   • If you’re using store-bought cookie dough, skip this step. Otherwise, here’s how to make homemade dough:
     • In a large mixing bowl, beat the butter, brown sugar, and granulated sugar together until light and fluffy (about 2 minutes).
     • Add in the egg and vanilla extract, and beat until combined.
     • Slowly mix in the flour, baking soda, and salt until just combined, then stir in the chocolate chips.
3. Press the cookie dough into the pan:
   • Spread the cookie dough evenly across the bottom of your prepared pan. Don’t worry if it’s a bit sticky—just use your fingers or the back of a spoon to press it down evenly. This is your first layer, and it should cover the entire bottom of the pan.
4. Add the Oreo layer:
   • Take your Oreos and line them up on top of the cookie dough. You don’t need to overlap them, just create an even layer. It’s okay if there are some gaps between the cookies—they’ll still bake beautifully into the dough and brownies.
5. Prepare the brownie batter:
   • In a large mixing bowl, prepare the brownie mix according to the instructions on the box (typically adding eggs, oil, and water). If you want to add some extra flair, stir in some chopped nuts or chocolate chips at this stage.
6. Pour the brownie batter on top of the Oreos:
   • Gently pour the brownie batter over the Oreo layer, spreading it out with a spatula so it covers the cookies completely. Make sure it reaches all the edges of the pan so you get a nice, even layer.
7. Bake your brownies:
   • Pop your pan into the oven and bake for 35-40 minutes, or until the top of the brownies is set and a toothpick inserted into the center comes out mostly clean (a few crumbs are okay). If the top starts to brown too quickly, you can loosely cover it with foil.
8. Cool before cutting:
   • Once the brownies are done, remove them from the oven and let them cool in the pan for at least 10 minutes. For best results, let them cool completely before slicing—it helps everything set, and you’ll get cleaner layers.
9. Serve and enjoy:
   • Lift the brownies out of the pan using the parchment paper overhang, and slice them into squares. Each piece will have that gorgeous layered effect with cookie dough, Oreos, and brownies all in one bite.