Step 1: Preheat the Oven

Preheat your oven to 350°F (180°C) and prepare your baking pan. Grease a 9×13 inch pan and line it with parchment paper, leaving an overhang for easy removal. This step ensures your brownies don’t stick to the pan and makes cleanup a breeze.

Step 2: Prepare the Chocolate Chip Cookie Layer

Start by making the chocolate chip cookie dough. In a large mixing bowl, beat together butter, brown sugar, and granulated sugar until smooth. Once combined, add the egg, egg yolk, and vanilla extract, mixing until the dough is light and fluffy.

Next, add flour and salt to the dough, and mix until incorporated. Once the dough comes together, gently fold in the chocolate chips. This will create that perfect cookie dough texture—soft, thick, and sweet.

Spoon the cookie dough into your prepared pan and spread it out evenly, pressing it down with a spatula to create a smooth and even layer.

Step 3: Add the Oreo Layer

Place the Oreo cookies on top of the chocolate chip cookie dough layer, pressing them down gently. Arrange the cookies in rows, covering the entire surface. Don’t be afraid to overlap them slightly to ensure the entire layer is covered. The Oreos will provide a crunchy contrast to the soft cookie dough and brownie layers.

Step 4: Make the Brownie Batter

For the brownie layer, start by melting the butter and dark chocolate together in a microwave-safe bowl. Microwave on medium power in 45-second intervals, stirring between each one until smooth and melted. Once melted, let the mixture cool for about 5 minutes.

Next, whisk in the eggs and sugar until smooth and combined. Sift the flour, cocoa powder, and salt together to avoid any lumps, then whisk them into the wet ingredients until fully incorporated.

Step 5: Assemble and Bake the Brownies

Spoon the brownie batter on top of the Oreo layer, dropping spoonfuls across the pan. Then, spread it evenly to cover the entire surface, being careful not to disturb the Oreo layer beneath. Bake the brownies in the preheated oven for 37-45 minutes. Check for doneness by inserting a toothpick into the center—if it comes out clean or with a few moist crumbs, they’re ready.

The baking time may vary depending on your oven and how gooey you prefer your brownies. For extra fudgy brownies, err on the side of underbaking. For a more cake-like texture, bake a little longer.

Step 6: Cool and Slice the Brownies

Once baked, remove the brownies from the oven and let them cool completely. The cooling process is important to ensure that the brownies set and slice easily. For best results, let them cool at room temperature for at least 4 hours before lifting them out of the pan using the parchment paper overhang. Transfer to a cutting board and slice into 12-16 bars, depending on your preferred serving size.

Step 7: Enjoy

These slutty brownies can be enjoyed warm, at room temperature, or even cold. The chewy cookie dough, crunchy Oreos, and fudgy brownie come together to create the ultimate dessert experience. If you’re feeling extra indulgent, you can drizzle some warm caramel sauce over the top or serve with a scoop of vanilla ice cream for an over-the-top treat.