Mississippi Mud Cake is a legendary Southern dessert known for its ultra-moist crumb, molten marshmallow layer, and thick chocolate frosting. This cake is not delicate. Instead, it is bold, rich, and unapologetically indulgent. The name comes from the resemblance to the dark, dense banks of the Mississippi River. Every bite delivers deep chocolate flavor, soft texture, and a signature gooey finish.
This recipe is simple to prepare. However, it produces bakery-level results. Therefore, it is perfect for family gatherings, potlucks, holidays, or anytime you need a true comfort dessert.
What Makes Mississippi Mud Cake Special?
Unlike traditional chocolate cake, Mississippi Mud Cake combines several textures in one dessert.
- A dense brownie-style base
- A soft melted marshmallow layer
- A warm poured chocolate frosting
- A topping of toasted pecans
As a result, the cake forms its own layers without complicated techniques. The frosting melts slightly into the marshmallows, creating the iconic “muddy” texture.

Finished Mississippi Mud Cake
Notice the dense crumb, glossy frosting, and rustic appearance. This dessert should look homemade. Perfection is not required. Texture is the goal.
Ingredients Overview
Mississippi Mud Cake uses pantry staples. Yet, the balance of fat, cocoa, and sugar creates its distinctive richness.
For the Cake Base
- Unsalted butter
- Granulated sugar
- Eggs
- Vanilla extract
- All-purpose flour
- Unsweetened cocoa powder
- Salt
- Chopped pecans
For the Marshmallow Layer
- Mini marshmallows
For the Chocolate Frosting
- Butter
- Cocoa powder
- Milk
- Powdered sugar
- Vanilla extract
Each component contributes to the final texture. Therefore, substitutions should be made carefully.

Ingredient Setup
Preparing ingredients beforehand ensures smooth mixing and prevents overworking the batter.
Exact Ingredient Quantities
Cake Batter
- 1 cup (226 g) unsalted butter, melted
- 2 cups (400 g) granulated sugar
- 4 large eggs, room temperature
- 1 tablespoon vanilla extract
- 1 ½ cups (190 g) all-purpose flour
- ½ cup (50 g) unsweetened cocoa powder
- ½ teaspoon salt
- 1 cup (120 g) chopped pecans
Marshmallow Layer
- 4 cups mini marshmallows
Chocolate Frosting
- ½ cup (113 g) butter
- ⅓ cup (30 g) cocoa powder
- ⅓ cup (80 ml) milk
- 3 ½ cups (420 g) powdered sugar
- 1 teaspoon vanilla extract
Step-by-Step Preparation
Step 1 — Prepare the Pan
Preheat the oven to 350°F (175°C).
Grease a 9×13-inch baking pan thoroughly.
This cake is sticky. Therefore, proper greasing prevents tearing.
Step 2 — Mix Wet Ingredients
In a large bowl, combine melted butter and sugar.
Whisk until smooth.
Add eggs one at a time.
Mix well after each addition.
Stir in vanilla extract.
This creates the rich foundation of the cake.
Step 3 — Add Dry Ingredients
Sift flour, cocoa powder, and salt together.
Fold gently into the wet mixture.
Do not overmix.
The batter should remain thick and glossy.
Step 4 — Add Pecans
Fold chopped pecans evenly into the batter.
They provide crunch and balance the sweetness.
Step 5 — Bake the Cake
Spread batter evenly in the prepared pan.
Bake for 25–30 minutes.
The center should be set but still soft.
Avoid overbaking.
A fudgy texture is essential.
Step 6 — Add Marshmallows
Immediately sprinkle marshmallows across the hot cake.
Return to oven for 2–3 minutes.
Allow marshmallows to puff and soften.
They should melt slightly but not brown.
Step 7 — Prepare the Frosting
In a saucepan, melt butter over medium heat.
Stir in cocoa powder and milk.
Bring just to a simmer.
Remove from heat.
Whisk in powdered sugar and vanilla.
The frosting should be smooth and pourable.
Step 8 — Frost While Warm
Pour frosting directly over marshmallows.
Spread gently with a spatula.
The heat melts layers together into the signature texture.
Step 9 — Cool Before Cutting
Allow cake to cool completely.
This step is crucial.
It allows the layers to set properly.

Texture Science Behind Mississippi Mud Cake
This dessert works because of controlled moisture and fat ratios.
- High butter content creates density.
- Sugar retains moisture during baking.
- Marshmallows introduce gelatin structure.
- Warm frosting bonds layers together.
Therefore, the cake becomes neither brownie nor cake.
It exists somewhere uniquely between.
Tips for Perfect Results
Use Real Butter
Margarine contains water.
Butter provides proper richness and structure.
Do Not Overbake
Dry Mississippi Mud Cake loses its identity.
Frost While Cake Is Warm
This creates the signature fusion of layers.
Chop Pecans Finely
Large pieces disrupt slicing.
Common Mistakes to Avoid
Mistake: Waiting too long before adding marshmallows.
Result: They will not melt properly.
Mistake: Thick frosting applied cold.
Result: Layers separate instead of blending.
Mistake: Refrigerating too soon.
Result: Texture becomes dense rather than soft.
Serving Suggestions
Mississippi Mud Cake is rich. Therefore, simple accompaniments work best.
- Serve slightly warm for maximum gooeyness.
- Pair with black coffee.
- Add unsweetened whipped cream for contrast.
- Include vanilla ice cream for a classic Southern pairing.

Storage Instructions
At Room Temperature
Store covered for up to 3 days.
Refrigeration
Keeps up to 5 days.
Bring to room temperature before serving.
Freezing
Freeze slices individually for up to 2 months.
Variations You Can Try
Extra Chocolate Version
Add 1 cup chocolate chips to batter.
Walnut Substitute
Replace pecans with walnuts.
Espresso Enhancement
Add 1 teaspoon espresso powder to cocoa mixture.
Salted Mud Cake
Finish with light flaky sea salt.
Each variation preserves the core identity while adjusting flavor.
Why This Recipe Works for Gatherings
Mississippi Mud Cake is ideal for entertaining.
- Bakes in one pan
- Travels well
- Feeds a crowd
- Requires no decoration
- Improves in flavor after resting
It is both rustic and memorable.
Frequently Asked Questions
Is Mississippi Mud Cake a brownie or a cake?
It is structurally closer to a brownie but softer and more layered.
Can I omit marshmallows?
You can, but the dessert will lose its defining character.
Why is it called “mud” cake?
The dark, dense appearance resembles Mississippi River mud.
Can I make it ahead?
Yes. It tastes even better the next day.
Final Thoughts
Mississippi Mud Cake is not about elegance. Instead, it celebrates abundance, warmth, and deep chocolate comfort. The combination of fudgy cake, melted marshmallow, and glossy frosting creates a dessert that feels nostalgic and indulgent at the same time.
It is easy to prepare.
It is impossible to forget.
And it remains one of the most beloved Southern desserts ever created.
