These decadent, easy Mississippi Mud Brownies start with a brownie mix, topped with marshmallows, then drizzled with melted store bought canned chocolate frosting. Crazy, right? These are shortcut marshmallow brownies but they're NOT short on ooey gooey fudgy goodness!

I'm serious when I say these marshmallow brownies were my number one best seller when I catered many years ago. I've kept the recipe a secret for almost 20 years!
And now I'm sharing the 5 ingredient recipe (if you don't count water) with you for the first time!
The ingredients are simple but it's the techniques and timing I use that make these the BEST Mississippi Mud Brownies using brownie mix EVER!
And of course, it's a shortcut recipe!
You are going to be shocked when I also tell you the icing comes from a tub of store-bought frosting! I melt it and drizzle it over the softened marshmallows.
Out of all the brownie recipes I've tasted in my 20 years as a test kitchen professional, this is hands down one of the best (if not the best) Mississippi Mud recipes I've eaten.
My catering recipe vs family-size recipe
Mississippi Mud Brownie recipe for catering
Now, full disclosure, back when I catered, I typically made my marshmallow brownie recipe with a 20-ounce Hershey's triple chocolate brownie mix from Sam's Wholesale or 20-ounce Ghirardelli triple chocolate mix at Costco. I would double the mix and ingredients (using my own baking time) and made 3 dozen at a time in a full sheet pan.
Shortcut Mississippi Mud Brownie - family size
I've done the research for you!
I researched national brands of 18- and 20-ounce brownie mixes and chocolate frostings that I found in national grocery stores and tested each one twice.
The results were a Mississippi Mud Brownie recipe just like my locally-famous brownies you can make at home!
Note: I wanted to find the best brownie mix that was easily available to everyone that resulted in the same decadent brownie.
Along with my tricks, tips and techniques, the results are almost exactly the same! You can scroll down past the step by step directions if you want to see all the brands I tested for the winners and runners up. The winners are listed in the printed recipe, too.
What are Mississippi Mud Brownies?
Basically, they are fudge brownies topped with marshmallows and chocolate icing. They are also called Mississippi Mud Bars, Mudslide Brownies, and Marshmallow Brownies.
I've even heard them called "dirt brownies" but that doesn't sound appealing to me.
If you've ever had Mississippi Mud Cake, they're similar to that but even more rich, dense and decadent and slightly chewy! You can make them with milk chocolate brownie mix and frosting but I prefer the more intense dark chocolate flavor.
Shortcuts
- Not only is a brownie mix a shortcut vs making homemade brownies, this brownie mix has added chocolate chips which saves an extra ingredient to buy.
- Store bought "canned" frosting - Melting this frosting takes seconds in the microwave vs making a cooked, pourable chocolate icing from scratch.
- Mini marshmallows - I prefer sprinkling marshmallows over the warm brownies vs trying to spread messy marshmallow cream on them.
If you love blonde brownies try my Blonde Brownies with Cheaters Caramel Icing. They are similar to an iced soft and chewy caramel cookie.
Ingredients
What you will need to make this easy Mississippi Mud Brownie recipe:
Scroll down to printable recipe for exact ingredient quantities.
- Brownie mix- Ghirardelli Dark Chocolate or Double Chocolate- 20 ounce box
- Vegetable oil or canola oil
- Eggs
- Miniature marshmallows
- Chocolate frosting in a tub- Pillsbury or Duncan Hines chocolate fudge frosting
- Water
How to make Mississippi Mud Brownies
First, ignore the directions on the brownie mix box!
Scroll down to the bottom for the printable recipe with detailed instructions.
- Lightly beat eggs in a large bowl; stir in oil and water.
- Add brownie mix. Stir vigorously, about 40 times.
- Line pan with parchment paper or aluminum foil for easy removal from pan and cutting later on. Grease or spray with cooking spray, if using foil.
- Pour brownie batter into pan and spread to the edges.
- Bake according to directions in printable recipe below, not package directions.
- Remove baked brownies from oven and immediately cover with mini marshmallows.
- Cover with foil or lid and let stand 8 minutes to partially melt marshmallows.
- Meanwhile, melt frosting in microwave or stovetop according to printable recipe below.
- Drizzle frosting over marshmallows.
Tip: I like to drizzle starting at one corner and go across the brownies, then finish starting at the other corner. This leaves some of the marshmallows exposed so you know the are Mississippi Mud Brownies at a glance!
- Let the brownies cool to room temperature. Refrigerate 2 hours. They cut MUCH better if chilled at least one hour after cooling.
- Lift brownies from pan with parchment paper or foil onto a cutting board. Cut brownies into desired number of pieces. Calories are calculated in printable recipe for 15 pieces.
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And there you have it! My semi-famous Mississippi Mud Brownies recipe. Let me know in the comments below if you try them.
Substitutions & Variations
Trade "this" for "that" in this shortcut version of marshmallow brownies.
- Brownies with marshmallow creme- It's messy, but you can place small dollops of marshmallow cream (fluff) onto the warm brownies right from the oven. The dollops will slightly melt and spread when covered with the foil.
- Rocky Road Brownies - To make this a Rocky Road brownie recipe, sprinkle about ½ cup chopped almonds, peanuts or pecans along with the marshmallows.
- Melted butter- You can also use ½ cup (1 stick) of salted or unsalted, melted, butter instead of the oil.
- If you or your kids prefer a milder chocolate flavor, don't choose the dark chocolate brownie mix and drizzle with a milk chocolate frosting.
- Homemade Cosmic brownies - Do not melt the icing and just spread it on the cooled prepared brownies WITHOUT marshmallows. Sprinkle multi colored sprinkles or rainbow candy coated chocolate "chips" over the icing.
Can I bake these marshmallow topped brownies in a 9x9-inch pan?
The short answer is yes.
The pic above compares the results of baking these marshmallow fudge brownies in both a 9x9-inch baking pan and a 13x9-inch baking pan.
The marshmallow brownie on the left is baked in the smaller pan for an additional 5 minutes. The brownie on the right is baked in the 9x13 pan.
Best store bought brownie mix and chocolate frosting for Mississippi Mud Brownies
Again, I've done the research and testing for you. You can't take the test kitchen out of me! lol
Best brownie mix for this shortcut brownie recipe
I tested four national brands to determine the best box brownie mix for my Mississippi Mud Brownie recipe.
Notes: I reduced the baking time from the box directions on all of them. I increased the oil in some and decreased the water amounts on some of them.
All store bought brownie mixes I tried, except two, were 18 ounces and included chocolate chips or chunks.
- Ghirardelli premium brownie mix (double chocolate and dark chocolate) 20 ounces):
- Aldi specialty selected double chocolate premium brownie mix- 18 ounces:
- White Lily chocolate fudge brownie mix- 18 ounces:
- Betty Crocker supreme chocolate chunk brownie mix- 18 ounces:
Winning brownie mixes
For my Mississippi Mud Brownie recipe, the best store bought box brownie mixes from grocery stores were Ghirardelli Double Chocolate AND their Dark Chocolate mix (20 ounces).
Aldi's double chocolate mix comes in second mainly because it is only 18 ounces and doesn't make the brownies quite as tall.
If you shop at Sam's Wholesale, Hershey's triple chocolate brownie mix is amazing and comes with four (20 ounce) pouches and make fantastic Mississippi Mud Brownies with my recipe, too.
If you shop at Costco, they sell Ghirardelli triple chocolate brownie mix that comes with six (20 ounce) pouches. That was the very first brownie mix I used to make my catering brownies but no longer have a Costco membership.
So, there you have the winners to make my Mississippi Mud Brownies with brownie mix.
Best store bought chocolate frosting
I tested five national brands of canned ready-to-spread frosting (icing) in a tub (can) for my Mississippi Mud Brownies recipe. All containers were 16 ounces.
Note: These results are the best canned chocolate frosting for MELTING and drizzling, not necessarily the best frosting to frost a cake.
I melted all five of the frostings in the microwave and drizzled over the top of marshmallows and let cool to room temperature, then refrigerated for best cutting.
- Pillsbury creamy supreme chocolate fudge frosting
- Duncan Hines creamy dark chocolate fudge frosting
- Aldi's Baker's Corner chocolate rich & creamy frosting:
- Betty Crocker rich & creamy chocolate frosting:
- Walmart's Great Value chocolate frosting:
The best store bought canned chocolate frostings for melting and drizzling on Mississippi Mud Brownies is Pillsbury with Duncan Hines a close second, then Aldi and Walmart. My least favorite was Betty Crocker. It remained glossy and sticky after cooling.
Helpful Information
The main difference between Mississippi Mud Cake and its cousin, brownies with marshmallow topping is the density of the cake and brownie and how tall they are.
Mississippi Mud Cake is lighter and softer, made with more eggs and the batter is beaten longer to incorporate more air. The same is true whether it's made from scratch or with a cake mix.
Brownies are more dense and chewy, due to the amount of melted butter or oil and are baked less than a cake for that fudgy effect.
What to serve with Mississippi Mud Brownies
A Mississippi Mud Brownie is rich and decadent, so it's a good idea to serve them with something that balances their sweetness, unless you are serving them along with other desserts at a potluck.
- Vanilla ice cream is especially good with WARM chocolate brownies. My No Churn Peanut Butter Ice Cream would satisfy your chocolate-peanut butter craving.
- Coffee or milk
- Oreo Mint Truffles
- White Texas Sheet Cake (with Cake Mix)
Storage Tips
- To Store. Store any leftovers in the refrigerator, covered with foil or lid or in an air tight container. They slice much better when chilled and last longer in the fridge. They can be stored at room temperature, too.
- To Freeze. You can freeze Mississippi Mud Brownies but the store bought frosting lightens up in color and isn't as rich and smooth as fresh baked.
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Mississippi Mud Brownies (with Brownie Mix)
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Equipment
Ingredients
- 2 large eggs
- ½ cup vegetable or canola oil
- 2 tablespoons water
- 1 (20-ounce) box Ghirardelli double chocolate OR dark chocolate brownie mix
- 1 (10-ounce) package miniature marshmallows
- 1 (16-ounce) can (container) ready-to-spread Pillsbury chocolate fudge frosting or Duncan Hines dark chocolate frosting
Instructions
- IGNORE the directions on the brown mix box!
- Preheat the oven to 350F degrees.
- Line a nonstick 13x9 baking pan or baking dish with parchment paper or aluminum foil. If using aluminum foil or a pan that is not nonstick, spray with vegetable cooking spray. You can also grease the pan and foil. No need to grease parchment paper.
- Lightly beat the eggs together with a sturdy spoon in a large bowl. No need for a hand mixer. Add oil and water stirring well to combine. Then, stir in the brownie mix until combined. Stir vigorously about 40 times.
- Pour the brownie batter evenly into the parchment paper or foil lined pan, spread to the edges.
- Bake, uncovered, for 18 minutes. (SEE NOTES for baking time for 9x9 pan.) A toothpick inserted in center will not come out clean but should not be completely wet either. Brownies will firm up as they cool.
- Remove the pan of brownies from the oven and place on a wire rack or on your stovetop. Immediately sprinkle the mini marshmallows evenly over the hot brownies. Immediately cover with aluminum foil or the pan's lid if it has one.Remove the foil after 8 minutes.This step is important to melt the marshmallows just enough!
- Spoon the frosting into a microwave-safe bowl. I like to use a glass measuring cup because it has a pouring spout on it. Microwave on HIGH for 25 seconds, then stir well. It should be a good pouring consistency. If it is a bit too thick, try 4 more seconds. (SEE NOTES to melt frosting on the stovetop.)
- Drizzle the frosting over the partially melted marshmallows. I start in one corner and drizzle half the frosting across the pan, then start in the opposite corner and drizzle across the other side. This allows some of the marshmallows to show through on the top.
- Allow the brownies to cool to room temperature. They are ready to eat, now, but they cut MUCH easier if refrigerated at least 1 hour first. I like to chill them for 2 hours.
- Carefully lift the brownies out of the pan with the parchment paper or foil. Place on a cutting board and cut into desired number of pieces. Calories are calculated below for 15 pieces.
- Store the brownies, covered, in the refrigerator so they will stay fresh longer and cut more easily. They can also be stored at room temperature. Enjoy!
Notes
Nutrition
Nutrition analysis on GritsAndGouda.com recipes are mostly calculated on an online nutrition calculator. I am not a dietitian and nutritional information is an estimate and can vary based on products used.
Cynthia Gowen
Has anyone ever used marshmallow fluff? If so how much?
Kathleen
I haven't used marshmallow fluff on this because it is very sticky, but I think one 7 ounce tub would work. If you dolloped tablespoonfuls onto the warm brownies right out of the oven, then top with foil, I think the dollops would spread enough for you. I do not think spreading the dollops yourself would work well because it would pull up the brownies as you spread it. Let me know if you try it this way!
Kayla
I used marshmallow fluff the first time I made them. Aside from me sticking to just about everything in the kitchen after I added the fluff, everything tasted DIVINE!!
Kathleen
Yes, marshmallow fluff has to be one of the stickiest substances on earth! So glad you liked the brownies. The mini marshmallows really are much easier to work with!
Kim
Taking these to the Georgia VS Mississippi State game tailgate today. GO DAWGS!
Our tailgate crew usually has a theme. I thought this would be perfect. So easy and quick to
Kathleen
I agree! They are perfect for tailgaiting! I've wrapped the individual pieces in plastic wrap before when traveling with them and that works well to pass out once you get there.
Marie
I have a friend that cannot get enough chocolate. If i bake her a chocolate cake with chocolate icing, she eats the icing off and throws away the cake! I am hoping this recipe is enough for her sweet tooth. I just pulled them out of the oven and waiting for the marshmellows to melt....icing is heated in the glass measuring cup ready to be poured on. I am betting this will be a winner with her for her birthday! Thanks for the easy recipe!
Kathleen
Happy birthday to your friend! Let me know if these rich, decadent chocolate brownies satisfied her sweet tooth!
Jodie Kay Baker Minor
This is THE most thorough, most research based, BEST brownie recipe that exists. Don’t even think about looking anywhere else. This is THE one. Now go preheat your oven. Your tastebuds are waiting!!!!!!
Kathleen
It was a labor of love to do the research and bring you the BEST version of my catering recipe! It makes me so happy that you love it so much! I call them my chocolate therapy! They make a bad day, good!
Kayla
I have been wanting to make Mississippi Mud Brownies for a while, but I couldn't find any recipes for brownies; only cake. I would say the new year is going to be great since it started off with finding this amazing recipe! Thank your for all of your time and work that you put into these and sharing such a delicious dessert. I don't usually gravitate to a particular person's recipes or website, but after looking at a few of your recipes....I'll definitely be coming to try more of them. These brownies were PHENOMENAL and I will be making them for a lifetime! Happy New Year!!
Kathleen
This truly started my New Year off in the best way! This recipe means a lot to me since it was my most popular item on my menu when I catered. I'm so glad you loved it. It means the world to me that you now want to make more of my recipes! Happy New Year to you and yours, too!
Kayla
I just wanted to stop by again and tell you that these brownies are still the best brownies that I have eaten in my 30+ years on this planet! I just happened to see your quick bio on the home page...I don't know how I missed that you lived or just worked in Alabama! That's where I am from! These brownies just became even tastier!! 😊
Kathleen
Wow! What a fantastic review for me to wake up to this morning! Thank you! Thank you! I'm so glad you love the Mississippi Mud Brownies. And I'm so glad to know you're from Alabama! I do love this beautiful state and all the hardworking farmers in it! You've made my day!