Oreo Brookie Layer Cake

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This Oreo Brookie Layer Cake is the dessert mashup of your dreams. With layers of chewy chocolate chip cookie cake, fudgy brownie, and soft Oreo-studded vanilla cake, all wrapped in rich chocolate buttercream and topped with ganache, Oreos, and cookies — it’s three desserts in one stunning showpiece.

 

Why You Will Love This Recipe

  • Three desserts in one incredible cake
  • Rich, layered textures: chewy, soft, and fudgy
  • Loaded with Oreos and chocolate
  • Perfect for birthdays and celebrations
  • A true showstopper for serious dessert lovers

 

Oreo Brookie Layer Cake – The Ultimate Dessert Mashup

What happens when a cookie, a brownie, and an Oreo cake walk into a bakery? You get the Oreo Brookie Layer Cake — a dessert so indulgent, so over-the-top, and so unapologetically rich that it defies all conventional cake logic. This is not your average layer cake. This is a triple-threat tower of cookie dough, fudgy chocolate, and cookies ‘n cream deliciousness.

Each layer of this cake brings its own personality. The bottom is a dense and chewy chocolate chip cookie cake that holds its shape yet stays soft. It’s the kind of base that makes you pause with that first bite and say, “Whoa.”

Next comes the brownie layer — thick, rich, and slightly gooey in the center, baked just to that perfect stage between cake and fudge. It melts in your mouth and adds deep chocolate flavor that anchors the entire dessert.

Then, sitting on top is a moist vanilla Oreo cake with Oreo crumbs and chopped cookies folded right in. It’s soft, slightly crumbly, and studded with bursts of cookie crunch.

Holding all this delicious chaos together is a silky chocolate buttercream. It’s not too sweet, but just rich enough to bridge each layer with a smooth chocolate hug. Each tier is frosted, stacked, and coated in a chocolate buttercream shell.

To finish? A glossy chocolate ganache drip, cookie crumbles, and even more Oreos and chocolate chip cookies crowning the top. This cake is dessert maximalism at its best — and yes, it tastes as incredible as it looks.

Despite its complexity, this cake is surprisingly manageable with a little planning. Each layer can be made ahead and chilled, then stacked and decorated at your own pace. And it slices beautifully, holding its shape while showing off those glorious layers.

It’s perfect for birthdays, celebrations, or any time you want to seriously impress. You’ll hear gasps when you cut into it — and silence once people start eating.

No need to choose between your favorite treats anymore. This cake delivers them all in one epic bite.

 

 

 

 

Servings

Serves: 12–14 slices

Time

Prep Time: 1 hour
Cook Time: 1 hour 20 minutes (total for layers)
Assembly Time: 30 minutes
Chill Time: 1 hour
Total Time: 3 hours 50 minutes

Ingredients

Chocolate Chip Cookie Cake
  • 3/4 cup (169g) unsalted butter, room temp
  • 3/4 cup (108g) brown sugar
  • 1/4 cup (52g) granulated sugar
  • 1 large egg
  • 2 teaspoons vanilla extract
  • 2 cups (260g) all-purpose flour
  • 2 teaspoons cornstarch
  • 1 teaspoon baking soda
  • 1/2 teaspoon salt
  • 1 1/4 cups (225g) semi-sweet chocolate chips
Brownie Layer
  • 1/2 cup (112g) unsalted butter
  • 6 oz semi-sweet chocolate, chopped
  • 1 1/4 cups (259g) granulated sugar
  • 1 1/2 teaspoons vanilla extract
  • 3 large eggs
  • 3/4 cup (98g) all-purpose flour
  • 2 tablespoons unsweetened cocoa powder
  • 1/4 teaspoon salt
Oreo Cake Layer
  • 1 2/3 cups (217g) all-purpose flour
  • 1 cup (207g) sugar
  • 1 1/4 teaspoons baking powder
  • 1/2 teaspoon salt
  • 3 egg whites, room temp
  • 1/2 cup (115g) sour cream
  • 1/2 cup (120ml) milk
  • 2 teaspoons vanilla extract
  • 3/4 cup (168g) unsalted butter, melted
  • 1/2 cup (61g) Oreo crumbs
  • 6 Oreos, chopped
Chocolate Buttercream
  • 1 1/2 cups (336g) butter
  • 1 1/4 cups (237g) shortening
  • 9 3/4 cups (1121g) powdered sugar
  • 2 teaspoons vanilla extract
  • 1 1/4 cups (123g) unsweetened cocoa powder
  • 5–6 tablespoons (60–75ml) water or milk
Ganache & Decorations
  • 4 oz semi-sweet chocolate chips
  • 5 tablespoons (75ml) heavy cream
  • 10 Oreos, crushed
  • Chocolate chip cookies and halved Oreos (for garnish)

Instructions

  1. Preheat oven to 350°F (176°C). Grease three 9-inch cake pans and line bottoms with parchment.
Cookie Cake:
  1. Cream butter and both sugars for 3–4 minutes. Mix in egg and vanilla.
  2. Whisk dry ingredients, then mix into butter mixture.
  3. Stir in chocolate chips. Press dough into prepared pan.
  4. Bake for 21–24 minutes. Let cool completely in pan.
Brownie:
  1. Melt butter and chocolate over simmering water. Let cool slightly.
  2. Whisk sugar, eggs, and vanilla. Combine dry ingredients separately.
  3. Mix cooled chocolate into eggs, then fold in flour mix.
  4. Pour into pan and bake for 35–38 minutes. Cool completely.
Oreo Cake:
  1. Whisk dry ingredients in a bowl.
  2. Whisk egg whites, sour cream, milk, and vanilla in another bowl.
  3. Combine wet and dry mixtures, then stir in butter, Oreo crumbs, and chopped Oreos.
  4. Pour into pan and bake 34–36 minutes. Cool completely.
Frosting:
  1. Beat butter and shortening until smooth. Add powdered sugar, cocoa, vanilla, and milk. Mix until fluffy.
Assemble:
  1. Level each layer if needed. Place cookie cake on base, frost top, sprinkle crushed Oreos.
  2. Add Oreo cake, repeat frosting and crushed Oreos.
  3. Add brownie on top. Frost entire cake with buttercream. Chill 20 minutes.
  4. Microwave cream until hot. Pour over chocolate chips. Let sit 5 minutes, then stir to make ganache.
  5. Drizzle ganache around edges. Spread on top.
  6. Garnish with halved Oreos and cookies.

Tips

  • Bake layers ahead and refrigerate until ready to assemble.
  • Chill cake between frosting steps for clean results.
  • Use a sharp knife dipped in hot water to slice cleanly.
  • Customize with your favorite cookies or add peanut butter chips!

 

 

 

 

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