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Irresistible Mississippi Mud Brownies include an easy homemade brownie recipe topped with warm gooey marshmallows and chocolate frosting.
There are so many things to love about this Mississippi Mud Brownie recipe, which is why it's a guaranteed crowd pleaser! This recipe was inspired by my Mississippi Mud Cake recipe that has gone viral on facebook–it's has nearly 30 MILLION views. Obviously you all love the chocolate/marshmallow combo as much as I do, so this brownie version is only appropriate.
How to make Mississippi Mud Brownies:
- Make the brownie batter. Mix cocoa powder and oil. Add softened butter and mix until smooth. Add sugar and mix well. Add eggs, one at a time, mixing after each addition. Add vanilla. Stir in flour and salt, just until combined.
- Bake. Pour batter into greased 9×13 inch pan and bake at 350 degrees F for 25-30 minutes or until a toothpick inserted into the center comes out clean.
- Add Marshmallows. Remove brownies from the oven and sprinkle the marshmallows evenly on top. Return to the oven for 2-3 minutes or until the marshmallows are puffed. Remove from oven and allow them to cool completely. Once brownies are cool, make the frosting.
- Make the Frosting. Add melted butter, cocoa powdered, evaporated milk, vanilla, and 2 cups of powdered sugar to a mixing bowl and beat with electric beaters until smooth. Add more powdered sugar, a cup at a time, mixing well, until you reach your desired frosting consistency. I usually use about 3 ¼ cups powdered sugar. Spread frosting over the cooled brownies.
Pro Tip for Cutting Frosted Brownies: Use a plastic knife! The frosting and marshmallows will cut smoother and easier, without making a sticky mess, if you use a plastic knife to cut the brownies.
Make Ahead and Freezing Instructions:
To Make Ahead: I almost like these brownies even better the second day. Something about the way the flavors blend together and settle after several hours makes them even more irresistible. I also feel like they're a little less “rich” on day two, and they are easier to cut. But, it may be hard to wait that long, so feel free to dig in right away. The frosting can be made up to 2 weeks in advance, stored in an airtight container in the fridge.
To Freeze: The brownies can be frozen frosted or unfrosted, covered well, for up to 3 months. Allow to come to room temperature before serving.
Don't miss my Mississippi Mud Cake recipe, or other Brownie recipes like:
- Raspberry Truffle Brownies
- Reese's Peanut Butter Brownies
- Caramel Poke Rocky Road Brownies
- Mint Brownies
You can also FOLLOW ME on FACEBOOK, TWITTER, INSTAGRAM and PINTEREST for more great recipes!
Mississippi Mud Brownies (Marshmallow Brownies)
Ingredients
For the Brownies:
- 1/3 cup unsweetened cocoa powder
- 1/2 cup oil, (vegetable or canola oil)
- 1/2 cup butter, , softened
- 2 cups granulated sugar
- 4 large eggs
- 2 teaspoons vanilla extract
- 1 1/2 cups all-purpose flour
- 1 teaspoon salt
- 3 cups mini marshmallows
For the Frosting:
- 1/2 cup butter, , melted
- 1/3 cup unsweetened cocoa powder
- 1/3 cup evaporated milk
- 1 teaspoon vanilla extract
- 3 – 3 1/2 cups powdered sugar
Instructions
- Preheat oven to 350 degrees F. Grease a 9×13” pan with non-stick cooking spray.
- In a large mixing bowl, pour oil over cocoa powder and mix.
- Add softened butter and mix until smooth. Add sugar and mix for 1 minute. Add eggs, one at a time, mixing after each addition. Add vanilla and mix.
- Add flour and salt and stir to combine.
- Pour batter into prepared pan. Bake for 25-30 minutes or until a toothpick inserted into the center comes out clean.
- Remove brownies from the oven and sprinkle the marshmallows evenly on top. Return to the oven for 2-3 minutes or until the marshmallows are puffed. Remove from oven and allow them to cool completely.
- Once brownies are cool, make the frosting.
For the frosting:
- Add melted butter, cocoa powdered, evaporated milk, vanilla, and 2 cups of powdered sugar to a mixing bowl and beat with electric beaters until smooth.
- Add more powdered sugar, a cup at a time, mixing well, until you reach your desired frosting consistency. I usually use about 3 ¼ cups powdered sugar.
- Spread frosting over the cooled brownies and cut into squares. I've found a plastic knife works best to cut them, or if you make them 1 day in advance they are much easier to cut.
Notes
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
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HAVE YOU TRIED THIS RECIPE?!
RATE and COMMENT below! I would love to hear your experience.
I originally shared this recipe May 2017. Updated January 2021.
Do I sift the powdered sugar
No need to sift the powdered sugar. Enjoy!
I used two boxes of brownie mix for the bottom. Tastes the same. Added chopped pecans in icing too. My favorite cake.
Do you use salted, or unsalted butter?
Hi Tara,
You can use either. Baking recipes usually mean unsalted butter (especially if you see salt added, like in this recipe). If you have salted butter you can just cut down on the salt in the recipe 🙂
What is the difference between the cocoa in the brownie recipe and the unsweetened cocoa in the frosting recipe?
They are the same 🙂 Sorry–I just edited them to be consistent.
These were absolutely delicious! My husband, who is not crazy about chocolate brownies of any type, remarked about these being the best he’s ever had!
Thank you. Will be making these often.
Can you use regular milk if you don’t have any evaporated milk or will it make a difference to the taste thank you
Absolutely, it will still taste great! If you can, I would suggest a higher fat milk—-2% or whole milk.
Do you use all-purpose flour or self-rising flour.
All purpose flour!
These are by far one of the most amazing brownies I have ever had. Love them!
My brownies did not cook all the way through, so the entire inside was mush! 🙁 But the parts that were done, were AMAZING!!!
Did you uze a 9×13 cake pan ? And you use plain baking flour.
I had the same problem. The time does not cook them long enough
Hmm. Where you using a metal or glass baking pan? You elevation and humidity could have also played a role. Next time try placing a piece of tinfoil over the brownies and cook them longer, until a toothpick inserted into the center comes out clean.
Had the family over for dinner on Mother’s Day. I made this cake and pecan pie for dessert. The cake was so amazing that the pie was not even touched! Everyone loved the cake!
I did not have enought cocoa powder so I used special dark for the cake, and the regular for the frosting. Even those who don’t care for dark chocolate loved it. This is a definite keeper. And I will continue to make the same way.
Thanks for sharing this recipe.
one advice i would really recommend is to skip her homemade brownie mix and just bake a box brownie. After that then melt marshmallows and make frosting. it will make the recipe a little better. No shade at the lady who has made up this recipe because the idea and frosting is really good, but the box brownie is better for this recipe. Another note is that i only added 2 cups of powdered sugar and it was really sweet so if u have a sweet tooth then the 3 1/4 cup might work, but the 2 cups for me is best. Overall your idea is great.?
I think the recipe is so good, are u saying to use a box because its easier for you cause this recipe is amazing