Gooey Mississippi Mud Pie Brookies: The Ultimate Fudgy Brownie & Chewy Cookie Bar Recipe

Prepare yourself for an extraordinary treat that promises to satisfy even the most intense chocolate cravings! These Gooey Mississippi Mud Pie Brookies are not just any dessert; they are a masterpiece of layered indulgence, expertly combining the best of a rich, fudgy chocolate brownie with a soft, intensely chewy chocolate chip cookie. What makes them truly special is the generous scattering of crunchy pecans and delightful melt-in-your-mouth mini marshmallows, creating a symphony of textures and flavors in every single bite.

Oh, the sheer joy of rediscovering an old culinary obsession! It truly feels like ages since I last whipped up a batch of Brookies. There was a glorious period when I was utterly captivated by this magical brownie-cookie fusion, finding myself unable to resist its siren call. The combination of fudgy brownies and chewy cookies is simply irresistible, a perfect blend for those who truly can’t decide between two dessert favorites. Well, my friends, I’m thrilled to announce that the obsession has officially resurfaced, and it’s stronger than ever with this incredible Mississippi Mud Pie twist!

Just last weekend, as I pondered what delectable delight to share with you this month, my thoughts naturally drifted to what truly resonates with dessert lovers. I recalled a conversation where Joan, a dear friend and fellow baking enthusiast, shared how immensely popular her Mississippi Mudslide Cake was among her readers. This sparked an idea: a mud pie cookie. But why stop at just a cookie? I craved something extra decadent, intensely chocolatey, and undeniably gooey. And then, like a bolt of inspiration, the concept of brookies flashed into my mind. The transformation was instant: Mississippi Mudslide evolved into Mississippi Mud PIE Brookies. Yes, that’s a mouthful of “Mississippi,” but trust me, every syllable is worth it for this delightful, layered creation that delivers on every promise of rich, gooey goodness!

What Exactly Are Brookies? The Ultimate Dessert Hybrid

For those unfamiliar with this glorious hybrid, a “brookie” is essentially the perfect marriage of a brownie and a cookie, baked together in one harmonious pan. It’s a genius invention that eliminates the need to choose between two beloved desserts. Imagine sinking your teeth into the rich, dense chewiness of a brownie, immediately followed by the comforting softness of a classic chocolate chip cookie. When I create brookies, I always aim for that magnificent double-layer effect. You get the deep, fudgy chocolate brownie forming the rich, moist foundation, perfectly complemented by a soft, chewy chocolate chip cookie layer resting on top. This creates an unparalleled textural contrast that makes every bite an adventure. It’s the ultimate solution for anyone who can’t decide between a rich brownie and a classic cookie – why settle for one when you can have both, combined into a singular, extraordinary bar?

The Mississippi Mud Pie Magic: Pecans and Marshmallows Galore

To truly elevate these to “Mississippi Mud Pie” status, I’ve generously incorporated the classic elements that define this beloved Southern staple: crunchy pecans and sweet mini marshmallows. And I didn’t just mix them in; I layered them strategically for maximum impact! The pecans provide a wonderful, satisfying crunch that cuts through the richness of the chocolate. I’ve added them not only into the luscious cookie dough but also sprinkled a generous layer directly on top of the brownie batter before adding the cookie layer. This ensures a delightful, nutty crunch in every forkful, adding depth and complexity to the overall experience.

Similarly, the mini marshmallows are given the royal treatment to ensure that signature gooey texture. They’re folded into the cookie dough and also sprinkled over the brownie layer, ensuring that you get those irresistible, ooey-gooey, melted marshmallow pockets throughout every single piece. As these brookies bake, the marshmallows soften and slightly caramelize, adding a fantastic chewiness and a hint of sweet vanilla that perfectly complements the robust chocolate. This dual-layer, dual-inclusion method for both pecans and marshmallows guarantees that rich, complex texture and flavor profile that makes these Mississippi Mud Pie Brookies utterly unforgettable. It’s a technique I’ve successfully employed before, as seen in my Marshmallow Oreo Brookies, and it never disappoints in delivering an explosion of flavor and texture!

Initially, I considered bringing these tantalizing treats to my coworkers on Monday, envisioning their delighted faces. But then a far more tempting thought occurred: why not stash them in my freezer for a future rainy day indulgence? A personal stash of these delightful Gooey Mississippi Mud Pie Brookies felt like a much-needed act of self-care and a guaranteed source of happiness on any given afternoon. Just don’t tell my coworkers, mmmkay? Some secrets are just too delicious to share, especially when they involve such fudgy, chewy, and gooey perfection!

Simplified Baking: Harnessing the Power of a Brownie Mix

One of the best things about this recipe for Mississippi Mud Brookies is its clever and efficient use of a high-quality box brownie mix. This simple shortcut dramatically reduces prep time without compromising on flavor or that signature fudgy texture we all crave in a good brownie. You’ll simply prepare the brownie batter according to the package instructions – typically, this involves adding vegetable oil, large eggs, and water. While I’ve personally always used a box mix for this particular recipe, embracing its convenience and consistent results, I absolutely believe that a homemade brownie mix would yield an equally, if not more, spectacular result if you have the time and inclination to bake from scratch! Once your brownie batter is ready, spread it evenly over the bottom of your prepared baking pan. This forms the rich, dense, and wonderfully chocolatey foundation of your brookies, setting the stage for the delicious layers to come.

Crafting the Cookie Layer: A Symphony of Flavors and Textures

Next comes the equally important, and arguably even more exciting, cookie layer! While the brownie batter is patiently waiting in the pan, you’ll whip up a batch of your chocolate chip cookie dough from scratch. This is where the true “Mississippi Mud Pie” magic intensifies. Into this classic, buttery cookie dough, you’ll fold in even more of that magical goodness: a generous helping of finely chopped pecans for added crunch and plenty of delightful mini marshmallows for that signature gooey chewiness. The combination of these ingredients transforms a simple chocolate chip cookie into something truly extraordinary, imbuing it with deep nutty notes and pockets of melted sweetness.

Once your loaded cookie dough is ready, the layering process is simple yet effective, ensuring an even distribution of flavor and texture. I find it best to gently flatten chunks of the cookie dough with my hands, then carefully place them onto the brownie batter like pieces of a delicious puzzle, ensuring even coverage across the entire surface. Don’t worry about achieving perfect edges or a seamless top; as it bakes, everything melts and merges together into a beautiful, cohesive, and utterly irresistible dessert bar. The result is a visually stunning dessert that’s as “uber pretty” as it is incredibly delicious, a testament to the simple joy of combining two perfect treats. Hooray for beautiful and tasty baking that’s surprisingly easy!

The Grand Finale: Serving and Savoring Your Gooey Masterpiece

Now, if you’ll excuse me, it’s time for me to grab one of these absolute treasures from the freezer. But let’s talk about the ultimate serving experience, because these Mississippi Mud Brookies truly shine when enjoyed just right. While they are phenomenal straight from the pan (or even chilled from the freezer!), a quick warm-up in the microwave takes them to an entirely new level of gooey perfection. Imagine the fudgy brownie softening to its ideal melt-in-your-mouth consistency, the marshmallows melting into an irresistible, stretchy pull, and the chocolate chips becoming wonderfully molten. For an extra touch of sheer decadence, might I suggest a generous drizzle of warm hot fudge cascading over the top? Or, for the truly indulgent, a frosty scoop of vanilla ice cream perched on top, creating a delightful contrast of warm and cold? Now, that’s what I call a dessert experience! The interplay of fudgy, chewy, crunchy, and creamy – it’s a symphony of flavors and textures that will make your taste buds sing with delight.

Yield: 12-15 slices

Mississippi Mud Brookies Recipe Card

These Gooey Mississippi Mud Pie Brookies are the ultimate dessert bar, featuring luxurious layers of fudgy chocolate brownie and chewy chocolate chip cookies. Generously mixed with crunchy pecans and delightful mini marshmallows, they deliver an unforgettable combination of textures and deep chocolate flavor in every bite. Perfect for satisfying any sweet craving or sharing with loved ones!

Prep Time
15 minutes

Cook Time
25 minutes

Ingredients for Gooey Mississippi Mud Brookies

1 Box brownie mix (your favorite brand, yielding a 9×13 inch pan)
Ingredients required on the box (typically vegetable oil, large eggs, water)
1 ½ cups mini marshmallows, divided
1 cup chopped pecans, divided
For the chewy chocolate chip cookie dough:
½ cup (1 stick) unsalted butter, softened
½ cup light brown sugar, packed
½ cup granulated sugar
1 Large egg
2 teaspoons pure vanilla extract
1¾ cup all-purpose flour
½ teaspoon salt
½ teaspoon baking soda
¾ cup mini chocolate chips

Step-by-Step Instructions to Bake Perfect Mississippi Mud Brookies

Preheat Oven: Preheat your oven to 350°F (175°C). Prepare a 9×13-inch baking pan by lining it with parchment paper or a baking mat, ensuring some overhang on the sides for easy removal.
Mix Brownie Batter: In a medium-sized bowl, combine the brownie mix with the egg, vegetable oil, and water, following the specific instructions provided on your brownie mix box. Beat until the batter is thoroughly mixed and smooth.
Spread Brownie Base: Pour the prepared brownie batter over the parchment or mat in your pan and spread it evenly across the bottom. This will be your rich, fudgy base layer.
First Topping Layer: Sprinkle ½ cup of the chopped pecans and ¾ cup of the mini marshmallows evenly over the brownie batter. Gently press them down slightly into the batter to ensure they adhere.
Cream Butter & Sugars (Cookie Dough): In a separate large bowl, soften the unsalted butter in the microwave for 10-15 seconds until pliable but not melted. Add both the light brown sugar and granulated sugar. Using an electric mixer, beat until the mixture is light, smooth, and fluffy.
Add Wet Ingredients (Cookie Dough): Incorporate the large egg and pure vanilla extract into the creamed butter and sugar mixture. Beat until the egg is thoroughly incorporated and the mixture is well combined.
Combine Dry & Wet Ingredients (Cookie Dough): In another separate small bowl, whisk together the all-purpose flour, salt, and baking soda. Gradually add this dry flour mixture to the wet cookie dough batter, mixing at a low speed until just combined. Once all the flour has been added, increase the speed to medium until a soft cookie dough forms. Finally, add the mini chocolate chips, the remaining ½ cup of pecans, and the remaining ¾ cup of marshmallows. Fold these delicious mix-ins into the cookie dough until evenly distributed.
Layer Cookie Dough Over Brownie: Take spoonfuls or flattened chunks of the prepared cookie dough and gently drop them onto the top of the brownie mixture in the pan. Carefully press them down slightly into the brownie batter, doing your best to cover the entire surface evenly. Don’t worry if it’s not perfectly smooth; it will spread and meld beautifully during baking.
Bake & Cool: Bake for 25-28 minutes at 350°F (175°C), or until the cookie layer is lightly golden brown and a toothpick inserted into the center comes out with moist crumbs (not wet batter). Remove the pan from the oven and allow the brookies to cool completely in the pan on a wire rack before cutting. Cooling completely is crucial for neat slices. If you used a baking mat or parchment paper, you can carefully lift the entire sheet of brookies out of the pan for easier cutting. If the brownie portion still seems too gooey to cut cleanly, I highly recommend refrigerating the pan for 30-60 minutes before slicing for perfectly sharp squares.

Did you make this recipe?

We’d love to see your creations! Please leave a comment on the blog below or share a photo of your delicious Mississippi Mud Brookies on Instagram using #MississippiMudBrookies and tag us! We can’t wait to see your fudgy, chewy masterpieces.

Explore More Delicious Brookie Recipes from Beyond Frosting

If you’ve fallen head over heels for these Mississippi Mud Brookies, you’re in luck! The world of brookies is vast and wonderfully creative, offering endless combinations of fudgy brownies and chewy cookies. Here are a few more irresistible variations to inspire your next baking adventure, all designed to satisfy your sweet tooth with double the deliciousness and unique flavor profiles:

Marshmallow Oreo Brookies

Experience the delightful crunch of crushed Oreos combined with gooey, melted marshmallows in this unique brookie variation. It’s a cookie-ception that’s utterly delicious!

Butterfinger Brookies

Indulge in the irresistible combination of rich chocolate, creamy peanut butter, and the distinctive crispy crunch of Butterfinger candy in these truly decadent brookies.

Thin Mint Brookies

Discover a refreshingly minty twist on the classic brookie! These feature everyone’s favorite Thin Mint cookies integrated seamlessly into the fudgy and chewy layers for a cool, chocolatey delight.

Do you love these Gooey Mississippi Mud Pie Brookies and crave more innovative dessert ideas? Make sure you stop by Beyond Frosting for an abundance of creative brookie recipes and other sweet treats! Happy baking, and happy indulging!