Description

This decadent Mississippi Mud Cake is a rich, chocolatey dessert featuring a moist cocoa-infused cake layered with a gooey marshmallow spread and topped with a silky chocolate ganache, toasted pecans, and optional toasted coconut. Perfect for chocolate lovers craving a luscious, indulgent treat that combines textures and deep flavors in every bite.

Ingredients

Scale

Cake Ingredients

16 tablespoons (227g) unsalted butter, cold
1/3 cup (28g) Dutch-process cocoa
1 cup (227g) hot water
2 cups (240g) King Arthur Unbleached All-Purpose Flour
2 cups (397g) granulated sugar
1 teaspoon baking soda
1/2 teaspoon table salt
1 teaspoon espresso powder
1/2 cup (113g) sour cream, at room temperature
2 large eggs, at room temperature
1 teaspoon King Arthur Pure Vanilla Extract

Marshmallow Topping

2 cups (246g) marshmallow spread, store-bought

Chocolate Ganache and Toppings

1 cup (170g) semisweet chocolate chips or chopped semisweet or bittersweet chocolate
1/2 cup (113g) heavy cream
1 cup (113g) pecans, toasted and diced
1 cup (85g) toasted coconut, optional

Instructions

Preheat and Prepare Pan: Preheat your oven to 350°F (177°C). Grease and flour a 9-inch by 13-inch cake pan thoroughly to prevent sticking.
Melt Butter and Mix Cocoa: Melt the cold unsalted butter in a heatproof bowl or saucepan. Stir in the Dutch-process cocoa powder and the hot water until well combined, creating a smooth cocoa mixture.
Combine Dry Ingredients: In a separate large bowl, whisk together the all-purpose flour, granulated sugar, baking soda, table salt, and espresso powder until evenly mixed.
Mix Wet and Dry Ingredients: Pour the warm cocoa mixture over the dry ingredients. Stir gently to blend; expect the batter to be somewhat lumpy at this stage.
Add Sour Cream, Eggs, and Vanilla: Add the sour cream, eggs, and vanilla extract to the batter. Beat the mixture until it is nearly smooth, though a few small lumps can remain without affecting the texture.
Bake the Cake: Pour the prepared batter evenly into the greased and floured cake pan. Bake in the preheated oven for 30 to 45 minutes, or until a toothpick or cake tester inserted in the center comes out clean.
Apply Marshmallow Layer: Remove the cake from the oven and let it sit for one minute. Spoon the marshmallow spread over the top of the cake, wait an additional two minutes, then gently spread it evenly across the surface. Allow the cake to cool to lukewarm, approximately one hour.
Prepare Chocolate Ganache: In a microwave-safe bowl, combine the semisweet chocolate chips and heavy cream. Heat in the microwave for 60 to 90 seconds until the cream is very hot. Stir continuously until the chocolate completely melts and the ganache becomes smooth and glossy.
Assemble the Cake: Drizzle the warm chocolate ganache evenly over the cooled cake with the marshmallow layer. Immediately sprinkle the toasted and diced pecans over the ganache, followed by the optional toasted coconut, if using.
Storage: Store the finished cake well covered at room temperature for up to one day, or refrigerate for up to a week to maintain freshness and texture.

Notes

Allowing the eggs and sour cream to come to room temperature helps create a smoother batter and better cake texture.
To toast pecans and coconut, spread them on a baking sheet and bake at 350°F for 5 to 10 minutes, stirring occasionally to prevent burning.
Marshmallow spread can be found in the baking aisle of most grocery stores; if unavailable, mini marshmallows lightly melted and spread may work as a substitute.
For a deeper chocolate flavor, use bittersweet chocolate in place of semisweet chocolate in the ganache.
This cake is best served at room temperature or slightly chilled for optimal texture and flavor.

Prep Time: 20 minutes
Cook Time: 40 minutes
Category: Dessert
Method: Baking
Cuisine: American

Keywords: Mississippi Mud Cake, chocolate cake, marshmallow cake, chocolate ganache, pecan cake, rich chocolate dessert, cake recipe