Easy Mississippi Mud Cake Recipe (Made with Cake Mix)

Why You’ll Love This Mississippi Mud Cake Recipe

This easy Mississippi Mud Cake starts with a boxed cake mix that tastes homemade thanks to a few simple swaps. By replacing the ingredients called for on the box with a few better options, you get a rich, moist chocolate cake with very little extra work. I use the same trick in my carrot cake recipe too.

Everything is mixed by hand, so there are no mixer bowls or beaters to wash. The frosting is also made by hand and reminds me of the icing on Texas Sheet Cake and Lunch Lady Brownies.

What is Mississippi Mud Cake?

Mississippi Mud Cake is a rich chocolate cake topped with a layer of mini marshmallows and chocolate frosting or icing. This classic Southern dessert is a chocolate lover’s dream.

The exact origin of the name isn’t known, but many believe the dark, gooey appearance resembles the muddy banks of the Mississippi River.

This old-fashioned cake is a favorite for potlucks, holidays, and family gatherings throughout the South.

Ingredient Notes

• Cake Mix: Milk chocolate, Devil’s food, or chocolate fudge are all great options. You will not need the exact ingredients specified on the box. 
• Milk: I use whole milk but you can use low-fat milk, or even dairy free milk, if that is what you have on hand.
• Eggs: We use large room temperature eggs. 
• Melted Butter: Unsalted butter is used in the cake instead of oil and also in the frosting. 
• Mini Marshmallows: The mini ones are the perfect size to top the cake and melt into a gooey layer.
• Cocoa: Unsweetened cocoa powder is what gives our frosting rich chocolate flavor. 
• Powdered Sugar: This is the base for many great frostings and toppings.
• Vanilla Extract: I use pure vanilla extract, but vanilla flavoring will also work.

How to Make Mississippi Mud Cake

1. Melt the butter for the cake in a small saucepan or skillet over low heat, allow to cool completely. See tips below.
2. Preheat the oven to 350° and coat a 9″ X 13″ pan with nonstick cooking spray.
3. In a large bowl, mix the cake mix, eggs, milk and melted butter together with a whisk or large spoon. Pour the cake batter into the prepared pan and bake for 28-33 minutes or until a toothpick inserted into the center comes out clean. The top of the cake will spring back when touched and the sides will pull away from the pan when the cake is done. 
4. Sprinkle marshmallows onto the hot cake in an even layer, return to the oven and bake until the marshmallows just start to brown, about 3-5 minutes. This time may vary so watch them closely so they don’t burn. Let cool completely. 
5. Melt the butter and make the frosting by placing all of the ingredients into a large mixing bowl and mixing with a whisk or large spoon. Pour the warm icing over the marshmallows and spread into an even layer using a spatula or spoon. For best results cool completely so the icing sets up before cutting and serving. 

Tips for the Best Mississippi Mud Cake

• Melt butter for the cake mix and frosting separately. 
• When you melt the butter for the cake take the eggs and milk out of the fridge and let them come to room temperature while the butter cools. The butter will be cool and the eggs and milk will be room temp after about 30-45 minutes, depending on the temperature in your house.
• Cool the cake on a cooling rack on a counter that is away from the warm oven. This is an important step! The first time I made this cake I didn’t let the cake and marshmallow topping cool long enough and when I poured the icing over it I just ended up with a mess. We still ate it but it didn’t look good and I didn’t have one layer of marshmallows and one layer of icing, they sort of mixed together. It was still tasty but not what I wanted. 
• I always sift my powdered sugar and cocoa to get any large lumps out so my icing is as smooth as possible. I do this by putting them into a mesh strainer and pushing it through with the back of a large spoon. 

Add Pecans for Crunch

There are versions of this cake that include pecans for a little crunch. Add about 1 cup of toasted chopped pecans either on top of the marshmallow layer before you add the icing or on top of the icing. 

Storage 

Store in an airtight container at room temperature for up to 3 days or in the refrigerator for up to 4 days. You can also freeze individual slices or the whole cake for up to 3 months. Thaw completely before serving.

I haven’t frozen this cake myself, but I’ve frozen other cakes with great results. 

FAQs

More Easy Cake Mix Desserts

• Easy Banana Cake with Cake Mix
• Easy Hostess Inspired Snoball Cake
• Peach Cake with Cool Whip Frosting
• Easy Twix Poke Cake