Mississippi Mud Cake: The Ultimate Fudgy, Marshmallow-Gooey Southern Dessert

Prep Time: 15 minutes | Bake Time: 25–30 minutes | Serves: 9×13-inch pan

A Bite of Southern History

The Mississippi Mud Cake is a Southern classic, named for its rich, dark layers resembling the muddy banks of the Mississippi River. Originating in the mid-20th century, it became a beloved dessert due to its simple ingredients and decadent chocolatey texture. Over the years, bakers perfected it by adding marshmallows and a pourable fudge icing that seeps into every layer, creating a moist, gooey cake loved by generations.

Ingredients — Cake

1 cup all-purpose flour (≈ 125 g)
1 cup granulated sugar (≈ 200 g)
½ cup unsalted butter (1 stick ≈ 113.5 g)
¼ cup unsweetened cocoa powder (≈ 25 g)
2 large eggs
½ cup buttermilk (≈ 120 ml)
1 teaspoon vanilla extract
½ teaspoon baking soda
¼ teaspoon salt
½ cup mini marshmallows (≈ 50 g)

Ingredients — Fudge Icing

½ cup unsalted butter (≈ 113.5 g)
¼ cup unsweetened cocoa powder (≈ 25 g)
½ cup whole milk (≈ 120 ml)
16 oz powdered sugar (≈ 4 cups ≈ 480 g), added gradually
1 teaspoon vanilla extract

Instructions

Step 1: Preheat & Prepare

Preheat oven to 350°F (175°C). Grease a 9×13-inch pan and lightly dust with cocoa powder or line with parchment paper.

Step 2: Make the Batter

Melt ½ cup butter in a medium saucepan over medium heat. Whisk in ¼ cup cocoa powder until smooth. Remove from heat. Stir in sugar, then eggs one at a time. Add vanilla extract and buttermilk and mix until glossy and smooth.

In a separate bowl, whisk together flour, baking soda, and salt. Gradually fold into the chocolate mixture until just combined. Batter should be thick and shiny.

Step 3: Bake the Cake

Pour batter into the prepared pan. Bake for 25–30 minutes or until a toothpick inserted in the center comes out with moist crumbs. Slightly underbaked center gives the classic fudgy texture.

Step 4: Add the Marshmallows

Sprinkle ½ cup mini marshmallows evenly over the hot cake immediately after removing it from the oven. Marshmallows will soften and partially melt, forming gooey pockets.

Step 5: Make the Fudge Icing

Melt ½ cup butter in a small saucepan over medium heat. Whisk in ¼ cup cocoa powder until smooth. Add milk and vanilla extract. Gradually add powdered sugar while whisking until thick but pourable. For thinner icing, add 1–2 tablespoons milk.

Step 6: Pour, Swirl & Set

Pour warm fudge icing over marshmallows, gently spreading it to seep through all pockets. Allow cake to cool completely before slicing. Serve warm for extra gooeyness.

Why This Cake is Special

Rich, indulgent chocolate flavor with a fudgy texture.
Gooey marshmallow pockets melt into every bite.
Silky, luscious fudge icing completes the decadent experience.
Perfect for gatherings, holidays, and special occasions.
Simple ingredients and easy steps make it approachable for all bakers.

Tips for Best Results

Do not overbake to maintain fudgy texture.
Use high-quality cocoa powder for deep chocolate flavor.
Pour icing while cake is warm to melt perfectly into marshmallow layer.
Optional toppings: chopped nuts, shredded coconut, or extra marshmallows.
Double the marshmallows for an ultra-gooey dessert.

Serving Suggestions

Serve slightly warm with vanilla ice cream.
Top with whipped cream or fresh berries.
Drizzle with caramel or hot fudge sauce for extra indulgence.
Pair with milk, coffee, or sweet iced tea.

Make-Ahead, Storage & Reheating

Make ahead: Bake a day ahead, add icing before serving.
Storage: Cover at room temperature up to 3 days or refrigerate up to 5 days.
Reheating: Microwave slices 10–15 seconds for warm, gooey texture.

Variations

Nutty Mud Cake: Add chopped pecans or walnuts.
Mocha Mud Cake: Add 1 tsp instant espresso powder to icing.
Peanut Butter Twist: Swirl 2–3 tbsp creamy peanut butter into icing.
Extra Marshmallow Madness: Layer marshmallows under and over icing.
Chocolate Chip Surprise: Fold mini chocolate chips into batter.

Fun Facts

Mississippi Mud Cake is taller and gooier than brownies. It can be baked as sheet cakes, cupcakes, or used in a trifle. Loved for its nostalgic flavor, gooey marshmallows, and rich chocolate layers.

Conclusion

This Mississippi Mud Cake is the ultimate Southern dessert. Fudgy cake, gooey marshmallows, and shiny fudge icing create pure chocolate bliss. Simple, indulgent, and unforgettable — perfect for any occasion. Enjoy a big slice with a cold glass of milk and savor every decadent bite.