Ultimate Cookie Dough Brownie Cake Step-by-step instructions

Before you start

Before you start, make sure you have two 9-inch round cake pans, parchment paper, and a wire cooling rack. Prepare the brownie mix according to the package instructions, but set aside the eggs, oil, and water as listed.

Have your butter softened for the cookie dough, and chop the chocolate for the ganache. If you're using a stand mixer, fit it with the paddle attachment. Allow enough time for the brownies to cool completely and the cookie dough to chill.

Instructions

Bake and chill

1. 1Bake the brownie layers
   Preheat the oven to 350°F (175°C). Grease two 9-inch round cake pans and line the bottoms with parchment paper. Prepare the brownie mix according to package directions using the eggs, oil, and water. Divide the batter evenly between the prepared pans and smooth the tops. Bake until a toothpick inserted in the center comes out with a few moist crumbs, about 25 to 30 minutes. Let the brownies cool in the pans for 10 minutes, then transfer to a wire rack to cool completely.
   Look for Brownies are set around the edges and slightly soft in the center.
   Safe temperature 160°F (71°C) internal temperature (egg dishes)
   Tip Don't overbake—brownies should stay fudgy.
2. 2Make the cookie dough
   In a large bowl, beat the softened butter, brown sugar, and granulated sugar together until light and fluffy. Beat in the vanilla extract. Reduce the mixer speed to low and gradually add the flour and salt, mixing until just combined. Fold in the semisweet chocolate chips. Press the cookie dough into a 9-inch round cake pan lined with plastic wrap, smoothing the top. Refrigerate for at least 30 minutes until firm.
   Look for Cookie dough is thick and holds together when pressed.
   Tip Chilling makes it easier to handle and stack.

The brownies should be fudgy and have a shiny, crackly top. Let them cool completely on a wire rack. The cookie dough should be firm and hold a clean edge when cut. You should be able to lift the disc easily with a spatula without it bending or cracking. The ganache should be smooth and pourable, with a glossy sheen and no lumps.

Stack and coat

3. 3Make the ganache
   Place the chopped chocolate in a heatproof bowl. Heat the heavy cream in a small saucepan over medium heat until it just begins to simmer. Pour the hot cream over the chocolate and let it sit for 2 minutes. Gently stir until smooth and glossy. Let the ganache cool slightly until it thickens to a pourable consistency, about 10 minutes.
   Look for Ganache is smooth, shiny, and coats the back of a spoon.
   Tip If ganache is too thick, whisk in a little warm cream.
4. 4Assemble the cake
   Place one brownie layer on a serving plate. Spread a layer of ganache over it, then place the chilled cookie dough disc on top. Press gently to adhere. Place the second brownie layer on top. Pour the remaining ganache over the cake, letting it drip down the sides. Use an offset spatula to smooth the top and sides if desired.
   Look for Layers are stacked evenly and ganache covers the top and drips down.
   Tip Chill the cake for 15 minutes before slicing for cleaner cuts.

The cake should have three distinct layers: brownie, cookie dough, brownie. The ganache should cover the top and flow down the sides in thick drips, pooling slightly at the base.

The surface should be smooth and even. When you press gently on the top, the cake should feel firm but give slightly. The cookie dough layer should be centered and not visible from the outside.

Set and serve

5. 5Finish and serve
   Sprinkle the mini chocolate chips over the top of the cake. Let the cake set at room temperature for about 20 minutes, or refrigerate for 10 minutes to speed up the process. Slice and serve.
   Look for Ganache is set but still glossy.
   Tip Use a sharp knife dipped in hot water for neat slices.

The ganache should be set and no longer sticky to the touch, but still glossy. The mini chocolate chips should be scattered evenly over the top. When you slice, the layers should hold together without crumbling, and the cookie dough should be soft and chewy. The cake should be at room temperature for the best texture and flavor.

Common mistakes

One common mistake is overbaking the brownies, which makes them dry and crumbly. Keep a close eye on them and start checking a few minutes early. Another issue is the cookie dough being too soft to stack—if it's not chilled enough, it can slide or break.

Be patient and let it firm up in the fridge for at least 30 minutes. When making the ganache, avoid overheating the cream or the chocolate can seize. Pour the hot cream over the chocolate and stir gently until smooth.

How to tell it’s done

The brownies are done when a toothpick inserted in the center comes out with a few moist crumbs, not wet batter. The internal temperature should reach at least 160°F (71°C) to ensure the eggs are fully cooked.

The cookie dough is ready when it's firm enough to hold its shape when pressed. The ganache is ready when it's smooth and glossy and coats the back of a spoon. The assembled cake should be chilled until the ganache is set but still shiny.

• Egg dishes: 160°F (71°C) in the thickest part