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ToggleI still remember the first time I pulled a pan from the oven and the kitchen filled with warm chocolate and cookie scent. That gooey mashup — a crisp cookie bottom, an Oreo center, and a fudgy brownie top — tugged at my fork before I even cooled the pan. In hardly any time I had a sweet, nostalgic dessert that felt like a hug.
I love this recipe because it is simple and forgiving. The steps are straightforward, pantry staples work fine, and boxed mixes like Ghirardelli Ultimate Chocolate speed things up. A 9×9 pan gives a snug Oreo grid and a slightly underdone center sets as it cools for the perfect pull.
These bars slice neatly after a 30-minute chill, stack well for parties, and travel for bake sales. Store at room temp for three days, refrigerate five to six, or freeze up to two months. If I can stir, layer, and bake, I know I will get bakery-level results in no time.
Meet the Most Indulgent Layers Ever
A stacked trio—chip cookie base, an Oreo center, and a fudgy top—hits every sweet note at once. I love how simple layers turn pantry staples into something over-the-top with almost no fuss.
Intro: A gooey mashup of cookie dough, Oreo cookies, and fudgy brownie bliss
I break down the signature trio: a buttery chocolate chip cookie dough base, a tidy oreo cookie grid, and a glossy brownie top that bakes into fudgy perfection. The contrast of textures—chewy cookie, creamy sandwich cookies, and a soft brownie finish—makes each layer sing.

Why You’ll Love It
- Easy: three simple steps—press cookie dough, add cookies, pour brownie batter.
- Nostalgic: deep chocolate and vanilla cream evoke classic bake-sale treats.
- Outrageous chocolate: a fudge brownie top gives real chocolate depth.
- Customizable: swap cookies, add caramel, or use Double Stuf oreos for a plush center.
Layer | Main Ingredient | Quick Tip |
---|---|---|
Base | Chocolate chip cookie dough | Press evenly for a sturdy foundation |
Middle | Oreo cookies / Double Stuf | Use Double Stuf for a creamier center |
Top | Fudge brownie batter | Bake until edges set and center jiggles slightly |
Origin and the name
Early 2010s bloggers like Kevin & Amanda and Rosie (The Londoner) helped these layered bars go viral. The name stuck as a playful label for the stacked cookie-Oreo-brownie bars. I call them a simple way to make an impressive dessert.
Ingredients, Tools, and Prep for Mouthwatering Slutty Brownies You Must Try
A little prep saves time: measured ingredients, lined pan, and a ready oven make baking smooth.
From-scratch chocolate chip cookie layer
For a 9 x 9 pan: 1/2 cup unsalted butter (melted), 3/4 cup packed light brown sugar, 1/4 cup granulated sugar, 1 large egg + 1 yolk, 2 tsp vanilla, 1 1/2 cups all-purpose flour, 1/2 tsp baking soda, 1/2 tsp salt, and 1 1/4 cups chocolate chips. I stir just to combine so the dough stays tender.
Fast-track chip cookie dough & Oreo layer
Use a 16-oz roll of refrigerated chip cookie dough to press into the pan when I don’t want to make cookie dough. Arrange about 18 oreo cookies in a snug grid for an even layer; Double Stuf gives a plush center.
Brownie mix and oven setup
Prepare one boxed brownie mix per package (oil, eggs, water). If the mix lacks chips, fold in 1/2 cup chocolate chips for ultimate chocolate. Line a 9 x 9 baking pan with parchment, preheat to oven 350, and bake 45–55 minutes until edges set and center is slightly underdone. Chill 30 minutes before slicing.

Tool | Usage |
---|---|
9 x 9 baking pan | Holds the three layers snug for uniform bars |
Parchment paper | Lifts the slab out cleanly and prevents sticking |
Mixing bowl & whisk | Combine wet ingredients and mix the boxed brownie mix |
Rubber spatula | Spread an even cookie dough layer and fold batter |
Sharp knife & cooling rack | Slice clean squares after a brief chill and cool evenly |
Quick prep notes: Spread the cookie dough evenly, set aside a parchment “sling” for easy lifting, and keep oreo cookies at hand so assembly is swift. Store bars in an airtight container at room temp (3 days), fridge (5–6 days), or freezer (2 months).
Nutrition Facts (approx., per serving, 1 of 16): Calories 320; Fat 16g; Sat Fat 8g; Carbs 42g; Sugar 29g; Protein 3g; Sodium 200mg; Fiber 2g.
Step-by-Step: Build, Bake, and Slice the Ultimate Chocolate Mashup
I walk through the process in clear steps so the layers bake evenly and cut clean. Line a 9 x 9 baking pan with parchment and preheat the oven to oven 350°F before you begin.

Assembly and baking
- Prep the base: Make or press cookie dough into an even layer, pushing into corners. If using refrigerated dough, press gently.
- Center cookies: Arrange about 18 oreos in a snug grid so the surface is covered.
- Mix the top: Prepare the brownie mix per package. Fold in 1/2 cup chocolate chips if the mix is plain, then pour brownie batter over the cookies and spread to the edges.
- Bake: Slide into the oven and bake minutes—typically 45–55 minutes—until edges are set and the center is slightly underdone. A toothpick should show moist crumbs.
- Cool and slice: Set aside the pan to cool, then chill 30 minutes for neat cuts. Lift with parchment and slice with a hot wiped knife.
Tips, variations, and storage
Add a caramel drizzle, swap oreos for peanut butter cups, or sprinkle extra chocolate chips on top before baking. For gooier bars, pull 5 minutes early; for firmer texture, bake toward the upper range.
Storage | Timing | Notes |
---|---|---|
Room temp (airtight container) | Up to 3 days | Keeps a tender cookie texture |
Refrigerator (container) | 5–6 days | Extra fudgy bars |
Freezer | Up to 2 months | Wrap individually, then place in an airtight container |
Ready to Bake, Share, and Savor
A quick trip to the pantry and a ready oven are all it takes to bake this nostalgic, chocolate-packed treat. I favor a 9 x 9 pan for neat squares and often switch between a chocolate chip cookie base from scratch or a chip cookie dough shortcut for speed.
The payoff is the same: a defined oreo layer, glossy brownie batter on top, and that rich chocolate aroma that makes these slutty brownies a crowd-pleaser. Warm a square 20–30 seconds in the microwave or pop it briefly in an air fryer to revive the crumb, then add ice cream or a glass of milk.
I’m grateful to the online community that turned this recipe viral. Bake a pan, rate the recipe, and tag me when your dessert lands on the table — I love seeing your spins, whether it’s extra eggs, a pinch of brown sugar, or a fudge brownie swirl.