Cookies & Cream Brownies Recipe: Fudgy Oreo-Style Brownies

Cookies and Cream Brownies elevate a boxed brownie mix with Oreo cookies both inside and on top, finished with a sweet marshmallow frosting and a drizzle of fudge sauce.

Love Cookies and Cream? Try related recipes such as Cookies and Cream Cupcakes, cookies, monkey bread, popcorn, or donuts for more Oreo-inspired treats.

Why You’ll Love these Cookies and Cream Brownies

If you want Oreo brownies, this is the best way to make them. The Oreos baked into the batter soften and meld with the moist brownie texture for perfect cookies-and-cream bites.

A marshmallow-flavored frosting, studded with extra chopped Oreo pieces, sits on top of the brownies and is finished with a glossy fudge drizzle. Every bite delivers chocolate, cream, and marshmallow flavors together for the ultimate Oreo brownie experience.

I originally made these in a 12-inch foil pizza pan for a playful shape, but the recipe also adapts perfectly to a classic 9×13-inch pan. If you use the pizza pan, plan on a few extra Oreos to fully cover the surface.

These brownies are:

• Easy to make: A boxed brownie mix, a package of Oreos, and a few pantry ingredients are all you need.
• Chocolate-forward: Dark chocolate brownies plus a quick fudge topping satisfy true chocolate cravings.
• Sweet and creamy: Marshmallow creme in the frosting gives the classic Oreo filling flavor in a fluffy topping.

Ingredients You’ll Need

*NOTE: Full ingredient amounts and printable instructions are included in the recipe card below.

• Oreo cookies – regular or Double Stuf work well.
• Dark chocolate brownie mix – a family-size box provides rich flavor that complements the Oreos.
• Egg(s), water, and oil – used as directed on the brownie mix box.
• Shortening – helps keep the frosting white; refined coconut oil or extra butter are workable substitutes.
• Butter – adds flavor to the frosting.
• Marshmallow creme – gives the frosting that classic cookies-and-cream filling taste.
• Powdered sugar and vanilla extract – to sweeten and flavor the frosting.
• Chocolate chips and light corn syrup – make a simple, soft-set fudge sauce for drizzling.

How to Make the Oreo Brownies

NOTE: Full ingredient amounts and the printable recipe card are below.

• Preheat the oven to 350°F. Lightly grease a 13×9-inch pan or line it with parchment paper leaving an overhang to lift the finished brownies out easily.

• In a large bowl, combine the brownie mix with the egg(s), water, and oil until well blended.
• Place about 15 Oreos in the bottom of the prepared pan, then pour the batter over and around the cookies, spreading gently to level. (If preferred, you can spread the batter first and press Oreos into it — either method works.)
• Bake at 350°F for 20–23 minutes, or until a toothpick inserted near the center comes out with a few moist crumbs. Remove from oven and allow to cool completely before frosting.

How to Make the Marshmallow Frosting

While the brownies cool, prepare the marshmallow frosting.

1. Beat the shortening and butter together until creamy.
2. Mix in the marshmallow creme and vanilla until combined.
3. Gradually add powdered sugar and blend until smooth. Set aside.

How to Make the Fudge Topping

Finish the brownies with a quick fudge sauce.

• Combine butter, corn syrup, and chocolate chips in a microwave-safe bowl. Heat for about 30 seconds, stir until smooth, and add a teaspoon or two of hot water if you prefer a thinner drizzle.

Assembling the Cookies and Cream Brownies

Once the brownies and frostings are ready, assemble the dessert.

1. Spread the marshmallow frosting evenly over the cooled brownies.
2. Scatter chopped or quartered Oreo cookies across the top.
3. Drizzle with the warm fudge sauce and let it cool until slightly set but still soft before cutting.

Serving and Storing

• Cut the brownies into 15 pieces and serve. If you used parchment, lift the entire slab from the pan for easier slicing.
• Store leftovers tightly covered with plastic wrap or foil, or in an airtight container.
• Keep at room temperature for 3–4 days for best texture and flavor.

Substitutions

• For a Little Debbie-style flavor, try an alternate frosting.
• If you prefer homemade brownies, use your favorite fudgy-brownie recipe instead of boxed mix.
• If you don’t want to use shortening, substitute refined coconut oil or additional butter (note that butter may tint the frosting slightly off-white).

These Cookies and Cream Brownies are dangerously delicious and easy to polish off if you’re not careful. They’re best when shared—although keeping a slice (or two) for yourself is perfectly acceptable.

If you make this recipe, please rate and review it in the comments below. Thanks!