Preheat the oven and line the dish

• Preheat the oven to 180 °C.
• Line a square baking dish with baking paper.

Press in the cookie dough base

• Press the chocolate chip cookie dough into an even layer in the bottom of the dish.

Add the Oreo layer

• Arrange the Oreo cookies in a single even layer over the cookie dough.

Make the brownie batter

• Whisk the brownie mix with the eggs, oil and water until smooth.

Assemble the layers

• Pour the brownie batter over the Oreos and spread it evenly to cover.

Bake

• Bake until the top is set and a skewer comes out with moist crumbs.

Cool and slice

• Let the brownies cool completely in the dish.
• Lift out and cut into squares.