Easy Mississippi Mud Cake Brownies

Indulge in rich, fudgy Mississippi mud cake brownies topped with gooey marshmallow cream and chocolate frosting that has just the right amount of sweetness.

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Whenever my mom made Mississippi mud cake growing up, it always felt like a special and indulgent treat. My first time making it, I remember thinking, “That’s it?” It seemed too easy and the list of ingredients too short. Surely there was more to it. But good news for me, and now for you, this Mississippi mud cake can be made more than just on special occasions.

What You’ll Need

Scroll down to the recipe card below this post for ingredient quantities, full instructions and tips for success.

Mississippi Mud Cake Brownies

• Butter – I use salted butter. If using unsalted butter, add 1/4 tsp salt.
• Cocoa Powder – I use regular cocoa powder but you could add dark chocolate cocoa powder for a deeper flavor.
• Eggs
• Flour
• White Sugar
• Vanilla
• Marshmallow Cream – Can use store bought or homemade.

For the Frosting

• Milk – I use whole milk but 2% will also work. Lower fat milk or milk alternatives will alter the flavor and/or consistency.
• Butter
• Cocoa Powder
• Vanilla
• Powdered Sugar
• Chopped Walnuts (optional)

Recommended Baking Supplies

• Hand Mixer
• Glass Mixing Bowl
• 9×13 metal pan
• Measuring cups and spoons
• Silicone spatula
• Silicone whisk
• Offset spatula
• Wire cooling rack

How to Make Mississippi Mud Cake Brownies

For the Batter

Preheat oven to 350 degrees F. Line at 9×13 pan with tin foil (if using a metal pan) and spray with cooking spray.

In a large bowl, combine melted butter, cocoa, eggs, flour, sugar and vanilla. Using a hand mixer or whisk, mix well until no lumps remain.

Pour batter into your prepared pan and bake for 18-22 minutes, or until a toothpick comes out clean. Do not over bake or your cake will be dry.

Remove from the oven and place on a wire rack. Using a silicone spatula, drop dollops of marshmallow cream on top of the hot cake.

Gentry spread the marshmallow cream so it covers the whole cake. (I recommend using an offset spatula for this step. See my tips for success for more details.)

For the Frosting

In a medium saucepan, combine milk, butter and cocoa. Whisk together and boil for 1 minute.

Remove the chocolate mixture from the heat and add vanilla (and nuts, if desired). Add the powdered sugar, whisking in one cup at a time, until you reach your desired consistency. Alternatively, you can pour the chocolate mixture into a bowl with the powdered sugar. Make sure to beat everything together well until no lumps remain.

Spread over the top of the marshmallow cream and let set until cool before cutting and serving.

Tips for Success

Use an offset spatula to spread the marshmallow cream. If you’ve ever used an offset spatula to spread frosting, you know why they are amazing. If not, trust me when I say that they are one of my favorite kitchen tools. Rather than being one straight utensil, like a butter knife for example, the handle is higher than the spatula. When you use it to spread frosting, you avoid getting it on your hands and you have more control over where it goes.

Metal pans work better than glass. For this recipe, I highly recommend baking it in a metal pan and then lining it with tin foil before spraying with non-stick spray. The reason for this is because it makes cutting and serving the cake easier. This is because you can use the sides of the tin foil like handles and lift the cake out of the pan. Pull the tin foil away from the edges of the cake, cut and serve.

Let cool completely before serving. Marshmallow cream isn’t going to set and become hard but it is sandwiched in between the cake and the frosting. Both of those need to cool and set so your cake doesn’t fall apart.

Recipe FAQs

How should I store leftovers?

Store any leftover Mississippi mud cake brownies in the fridge covered in an air tight container to maintain freshness. They will be good for 3-4 days.

Can I substitute the milk for a diary free alternative?

As with many recipes, substituting the regular ingredient for an alternative can change components of the recipe. It’s the same for this dessert. I haven’t personally tried using other types of milk but know that doing so could effect the flavor and texture of the base and the frosting. If you try it out, please let me know how it works for you!

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