Mississippi Mud Cake

This rich, gooey Mississippi Mud Cake is a Southern classic made with pecans, marshmallows, and a warm chocolate icing poured right over the top. Baked in a 9x13 pan so it's perfect for the holidays or just because.

Course Dessert

Cuisine American

Prep Time 15

Cook Time 30

Total Time 45

Servings

Calories 735kcal

Author Anne Clark | My Kitchen Serenity

Equipment

measuring cup(s)
measuring spoons
whisk
large microwave safe mixing bowl
9x13-inch metal cake pan `

Ingredients

CAKE

2 sticks butter, sliced into 8 chunks aka 1 cup
1-½ cups granulated sugar that's 1 cup plus ½ cup
½ cup light brown sugar packed down in your measuring cup
4 eggs room temperature is preferred
2 teaspoons vanilla extract
1-½ cups self-rising flour that's 1 cup plus ½ cup
2 cups chopped pecans
⅓ cup unsweetened cocoa powder
10 ounces mini marshmallows

ICING

3-½ cups confectioners sugar (aka powdered sugar) that's 3 cups plus ½ cup
⅓ cup unsweetened cocoa powder
¼ cup melted butter this is 4 tablespoons
½ cup whole or 2% milk
2 teaspoons vanilla extract

Instructions

CAKE

Preheat oven to 350F. Place a sheet of parchment paper (large enough so the sides overlap the two longest sides) in a 9x13-inch metal cake pan. Spray the parchment paper and the sides with non-stick spray. Note: You'll use the parchment paper to lift the cake out of the pan later.
In a large microwave-safe mixing bowl, add the butter chunks and cook on high for 30 seconds to soften the butter. Stir. Add 10 more seconds if the butter isn't quite softened. No need to completely melt the butter; you just want to soften it to a creamy texture.
2 sticks butter, sliced into 8 chunks
Add granulated sugar, brown sugar, eggs, and vanilla extract to the butter and stir well (do not beat with a mixer --- use a spoon or whisk).
1-½ cups granulated sugar, ½ cup light brown sugar, 4 eggs, 2 teaspoons vanilla extract
Stir in the flour, chopped pecans, and cocoa powder just until combined; do not overmix.
1-½ cups self-rising flour, 2 cups chopped pecans, ⅓ cup unsweetened cocoa powder
Pour the batter into the cake pan and bake on the center oven rack for about 20-30 minutes. DO NOT OVERBAKE. Check on the cake after 20 minutes just to make sure it's not being overcooked. Check for doneness when a wooden toothpick inserted in the middle of the cake comes out with crumbs and not batter.
Remove the cake from the oven and immediately top with the marshmallows.
10 ounces mini marshmallows
Prepare the icing while the cake is still hot.

ICING

Beat together the confectioners sugar, cocoa powder, melted butter, milk, and vanilla extract until smooth and creamy.
3-½ cups confectioners sugar (aka powdered sugar), ⅓ cup unsweetened cocoa powder, ¼ cup melted butter, ½ cup whole or 2% milk, 2 teaspoons vanilla extract
Spread the icing on top of the hot cake.
After the cake has completely cooled off, you can remove it from the pan using the parchment paper handles. To serve: cut the cake into 12 squares and serve on a pretty platter. Tip: The cake is easier to cut after its cooled off.

Notes

Recipe Tips

Don’t overbake the cake.
You want that rich, gooey texture...not a dry one. The cake is done when the edges look set but the center still has a little jiggle. It’ll firm up more as it cools.

Pour the icing while the cake is hot.
This is key! Right after you scatter on the marshmallows and they get soft and gooey, pour the icing on top. It’ll melt down into all the nooks and form that fudgy, crackly layer we all love.

Use room temp eggs if you can.
Helps everything mix together smoother, but it’s not a deal-breaker if you forget.

Grease your 9x13 pan well.
This cake is sticky business, so line with parchment or give it a good coating of butter or baking spray.

Let it cool a bit before slicing.
It’ll be easier to cut once the icing sets just a little, but no judgment if you sneak a warm piece with a spoon.

Substitutions and Additions

Use 1½ cups all-purpose flour + 2¼ teaspoons baking powder + ½ teaspoon salt instead of SR flour.

You can skip the pecans if needed or swap in toasted coconut flakes or crushed pretzels for crunch.

Stir in ½ cup of mini chocolate chips into the batter or sprinkle a handful on top with the marshmallows.

Swap ¼ cup of the milk in the icing with strong brewed coffee or espresso for a mocha twist.
For a “mudslide” version, add a light drizzle of caramel sauce over the top after the icing sets.

Nutrition