These Mississippi Mud Cake Brownies Are the Ultimate Holiday Crowd-Pleaser

If you want a dessert that disappears in seconds, look no further than these Mississippi Mud Cake Brownies. I remember making a massive batch of these for Christmas, and they were eaten up before the main course was even finished! There is something so nostalgic about the combination of fudgy cake, toasted pecans, and gooey marshmallows.

As a former pastry chef, I appreciate how this recipe balances textures so perfectly. You get the crunch from the nuts, the chew from the marshmallow, and the silkiness of the frosting. It truly feels like a decadent Southern tradition brought to life in your own kitchen.

Furthermore, using a jellyroll pan makes these Mississippi Mud Cake Brownies ideal for feeding a large family or a holiday party. You don’t need fancy equipment to make these look professional and taste like a high-end bakery treat. Let’s get into the details so you can bake a batch that will have everyone asking for the recipe.

Why You’ll Love This Mississippi Mud Cake Brownies Recipe

• Incredible Texture: You get a perfect contrast between the soft marshmallows and the crunchy toasted pecans.

• Massive Yield: Baking these in a jellyroll pan ensures you have enough servings for any large gathering or potluck.

• Rich Chocolate Flavor: The double-hit of cocoa in the batter and the frosting creates a deep, satisfying chocolate profile.

• Easy Cleanup: This one-bowl base means you won’t spend all night scrubbing dishes after your holiday baking session.

Bakery-Level Pro Tips for Perfect Texture

First, never skip the step of toasting your pecans before adding them to the batter. Toasting the nuts releases their natural oils and creates a much deeper, more complex flavor profile. Simply pop them in the oven for a few minutes until they smell fragrant and look slightly golden.

Second, pay close attention to the marshmallow stage during the baking process. You want the marshmallows to puff up and get slightly tacky, but not completely liquify. This creates that iconic “mud” look that makes Mississippi Mud Cake Brownies so famous across the South.

Lastly, always sift your powdered sugar for the chocolate frosting to ensure a professional finish. Tiny lumps of sugar can ruin the glossy look of your drizzle and affect the mouthfeel. A smooth, velvet-like frosting is what separates a standard brownie from an elite bakery-style dessert.

Ingredients You Will Need

For the Brownie Base:

• 1 Cup Melted Butter: You can use two sticks of butter or a mix of butter and margarine for a softer crumb.

• 2 Cups Sugar: Standard granulated sugar provides the sweetness and helps create a slightly crisp top.

• 1/2 Cup Unsweetened Cocoa: This provides the deep chocolate base for our Mississippi Mud Cake Brownies.

• 4 Large Eggs: Make sure these are lightly beaten to incorporate into the batter smoothly.

• 1 Teaspoon Vanilla Extract: Always use pure vanilla for the best aromatic results.

• 1/8 Teaspoon Salt: Just a pinch to balance the sweetness of the sugar and marshmallows.

• 1 1/2 Cups All-Purpose Flour: This gives our brownies enough structure to hold up all those heavy toppings.

• 1 1/2 Cups Coarsely Chopped Pecans: Ensure these are toasted for the best possible crunch.

• 1 Bag Miniature Marshmallows: A standard 10.5-ounce bag is the perfect amount for full coverage.

For the Chocolate Frosting:

• 1 Package Powdered Sugar: Use a 16-ounce bag and sift it thoroughly.

• 1/2 Cup Milk: This thins the frosting to a perfect drizzling consistency.

• 1/4 Cup Softened Butter: Use room temperature butter so it creams easily with the cocoa.

• 1/3 Cup Unsweetened Cocoa: This adds that final layer of chocolatey goodness.

USA Substitutions

If you are out of pecans, walnuts make an excellent substitute for these Mississippi Mud Cake Brownies. While pecans are the traditional Southern choice, walnuts offer a similar earthy crunch that pairs beautifully with chocolate.

For those who don’t have a jellyroll pan, you can use two 9×13-inch baking pans instead. Just be sure to adjust your baking time slightly, as the batter might be a bit thicker. Always check for doneness with a wooden pick to ensure the centers are fully baked.

If you prefer a darker chocolate flavor, try using Dutch-processed cocoa in the frosting. It provides a deeper color and a smoother, less acidic chocolate taste. This small swap can make your brownies taste even more like a gourmet bakery find!

Step-by-Step Instructions

1. Heat things up: Preheat your oven to 350°F and grease and flour a 15- x 10-inch jellyroll pan carefully.

2. Mix the base: In a large bowl, whisk together your melted butter, sugar, cocoa, beaten eggs, vanilla, and salt.

3. Add the dry ingredients: Stir in the flour and your toasted chopped pecans until the batter is just combined.

4. Bake the brownies: Pour the batter into the prepared pan and bake for 20 to 25 minutes until a pick comes out clean.

5. Add the “mud”: Remove the pan from the oven and immediately cover the warm cake with the miniature marshmallows.

6. Toast the top: Return the pan to the oven for exactly 5 minutes to let the marshmallows soften and puff.

7. Make the frosting: While the cake is in the oven, beat together the powdered sugar, milk, softened butter, and cocoa until smooth.

8. The final drizzle: Pour the warm chocolate frosting over the marshmallow layer while the cake is still warm.

9. The hardest part: Let the Mississippi Mud Cake Brownies cool completely before you even think about cutting them into squares!

Storage, Freezing, & Reheating

To keep your Mississippi Mud Cake Brownies fresh, store them in an airtight container at room temperature for up to three days. The marshmallows will stay softest if the brownies are kept away from direct air. If you need them to last longer, you can keep them in the fridge for up to a week.

These brownies also freeze surprisingly well for long-term storage. Wrap individual squares in plastic wrap and then place them in a heavy-duty freezer bag for up to three months. This is a great trick for saving leftover holiday treats for a rainy day!

When you want to eat a frozen brownie, let it thaw on the counter for about an hour. If you like them extra gooey, a quick 10-second zap in the microwave will soften the marshmallows beautifully. Just be careful not to overheat them, or the frosting will melt right off!

Frequently Asked Questions about Mississippi Mud Cake Brownies

Why did my marshmallows disappear into the cake? This usually happens if the marshmallows are added too early or if they are baked for too long. Make sure the brownie base is fully baked before adding the marshmallows for that final 5-minute puff.

Can I make these without nuts? Absolutely! You can simply omit the pecans if you have an allergy or just prefer a smoother texture. The brownies will still be incredibly delicious and fudgy.

How do I get clean cuts on these brownies? The secret is patience! You must let the Mississippi Mud Cake Brownies cool completely so the frosting and marshmallows set. Use a sharp, slightly wet knife for the cleanest slices.

Southern Mississippi Mud Cake Brownies

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Ingredients Method

Ingredients

  

• 1 cup melted butter or 1 stick butter + 1 stick margarine
• 2 cups granulated sugar
• 1/2 cup unsweetened cocoa powder
• 4 large eggs lightly beaten
• 1 tsp vanilla extract
• 1/8 tsp salt
• 1 1/2 cups all-purpose flour
• 1 1/2 cups toasted pecans coarsely chopped
• 1 10.5 oz bag miniature marshmallows
• Frosting: 1 16 oz pkg sifted powdered sugar, 1/2 cup milk, 1/4 cup softened butter, 1/3 cup cocoa powder

Method

 

1. Preheat your oven to 350°F. Grease and flour a 15- x 10-inch jellyroll pan.
2. In a large bowl, whisk together melted butter, sugar, cocoa, eggs, vanilla, and salt.
3. Gently stir in the flour and toasted pecans until well incorporated.
4. Pour the batter into the prepared pan and bake for 20-25 minutes.
5. Remove from oven and immediately top the warm cake with miniature marshmallows.
6. Return to the oven for 5 minutes.
7. While baking, beat the frosting ingredients together with an electric mixer until smooth.
8. Drizzle the chocolate frosting over the warm marshmallow layer.
9. Allow the brownies to cool completely before cutting into squares.