Dessert Bars

Mississippi Mud Brownies

Pinterest LinkedIn Tumblr

Mississippi Mud Cake is one of those desserts that manages to be so easy but so divinely delicious. So, as I have been looking for ways to spice up a basic brownie, Mississippi Mud Brownies seemed like the perfect solution. Rich, fudgy brownies with soft, fluffy marshmallows, all topped with chocolate icing. They are decadent yet so simple that you’ll find yourself wanting to make them again and again. Enjoy!

mississippi mud brownie on white plate with marshmallows

Mississippi Mud Brownies

Yield: 20
Prep Time: 40 minutes
Cook Time: 40 minutes
Additional Time: 1 hour
Total Time: 2 hours 20 minutes

Rich, decadent brownies with fluffy marshmallows and chocolate icing. A fun twist on a Mississippi Mud Cake.



  • 1 (4oz) package of unsweetened chocolate
  • 3/4 cup salted butter
  • 2 cups granulated sugar
  • 3 large eggs
  • 1 teaspoon vanilla
  • 1 cup all-purpose flour
  • 6 cups mini marshmallows


  • 1/2 cup salted butter
  • 6 tablespoons milk
  • 4 tablespoons cocoa powder
  • 1 teaspoon vanilla extract
  • 3 cups powdered sugar


  1. Preheat the oven to 350°F. Either spray a 9x13" pan with non-stick spray or line with foil, then spray the foil with non-stick spray. Set aside.
  1. Melt chocolate and butter in a microwave-safe bowl or in a medium saucepan on the stove. Stir in sugar. Blend in eggs and vanilla. Add flour and mix until fully combined (careful not to over-mix). Pour into the baking pan.
  2. Bake for 25 to 30 minutes or until a toothpick inserted in the center comes out with fudgy crumbs. Top with the 6 cups of marshmallows and return to the oven for an additional 2 minutes until the marshmallows have puffed up and are starting to melt. Set aside to cool at room temperature.
  3. While brownies are cooling, melt butter in a small saucepan. Mix in the milk and cocoa powder. Bring to a simmer and cook for 2-3 minutes, stirring constantly. The mixture may separate and look a little lumpy but that's okay.
  4. Remove the cooked butter mixture from heat and put into a mixing bowl with the vanilla and powdered sugar. Use a hand mixer and beat until smooth.
  5. While the icing is still warm, pour over the top of the marshmallows and spread gently.
  6. Chill in the refrigerator for 30 minutes.
  7. Serve.


Watch your marshmallows carefully, you don't want to overbake, or they will get too crispy/chewy.

Nutrition Information:
Yield: 20 Serving Size: 1
Amount Per Serving: Calories: 341Total Fat: 13gSaturated Fat: 8gTrans Fat: 0gUnsaturated Fat: 4gCholesterol: 59mgSodium: 117mgCarbohydrates: 55gFiber: 1gSugar: 45gProtein: 3g

Nutrition information is an estimate only.

If you’re looking for more great brownie recipes, check out these unique brownie recipes. If you’re having any issues with your brownies, here’s a great article on how to make amazing brownies.


Mississippi Mud Brownies can be stored for 2-3 days in an airtight container at room temperature and up to 5 days in the fridge.

Mississippi Mud Brownies can be frozen and should last for 2 to 3 months in the freezer if stored in an airtight container. They can be frozen as the entire pan or cut into slices. To freeze sliced brownies, firstly, freeze them on a sheet tray first (to keep them from freezing together.

Next, wrap the brownies in foil or cling wrap and finally, place them in an airtight container or freezer bag. Put parchment paper between the layers if you need to stack them.

How to thaw them depends on how you froze them. If you froze the entire pan, place it in the refrigerator overnight to thaw. If thawing a single brownie, put it on a plate at room temperature for 1 to 2 hours, then eat.

Where Did Mississippi Mud Cake Get Its Name?

When making these Mississippi Mud Brownies, I found myself wondering where Mississippi Mud Cake gets its name.

The generally accepted origin for Mississippi Mud Cake is that it was first created post-World War II in the Southern United States.

Apparently, people were excited to try out new packaged ingredients such as miniature marshmallows in their homemade treats. So when Mississippi Mud Cake was made with chocolate cake, marshmallows, and warm, gooey icing, it resembled the mud of the Mississippi River, and the name has stuck.

However, the same origin story is also reported for Mississippi Mud Pie. Typically mud pies consist of a chocolate crust, chocolate filling, and fluffy, creamy filling of cream cheese, vanilla pudding, marshmallow fluff, or some combination. Both mud pie and mid cake also frequently call for nuts in their recipes.

It isn’t clear whether mud pie or mud cake came first; however, I think most people can agree that you can’t go wrong when chocolate is involved.

If you like this peach pie for one recipe, let me know! Or if you’ve made the recipe let me know how it went. I’d love to hear from you in the comments. Happy baking!

Hello! I'm Nichole and I am a Registered Dietitian Nutritionist. I have a bachelor's degree in Nutrition, Dietetics and Food Science and a master's degree in Nutrition and Dietetics. I love cooking, baking and anything food related. I look forward to teaching you more about food and sharing my favorite recipes with you. Enjoy!

Write A Comment

Skip to Recipe