Made from scratch and stacked with three beautiful layers of deliciousness, these Marshmallow Brownies may look gourmet, but rest assured — they’re as easy as could be!
The bottom layer is everything you know and love about a brownie — soft and chewy, fudgy, and moist.
In the center lies a layer of high-rise, fluffy marshmallow, and to top it all off, a smooth, ganache-style chocolate icing (similar to what you might find poured over a Texas Sheet Cake)!
As you can imagine, these brownies are decadent, rich, and oozing with chocolatey, marshmallow goodness! They’re every kid (and grown-ups) dessert dreams come true!
This Marshmallow Brownie recipe (also known as Mississippi Mud Brownies) can be served any time of year, for any function or event! It’s a show-stopper dessert for holiday entertaining, an excellent addition to any summer BBQ, and an extra fun recipe for baking with kids.
HOW TO MAKE MARSHMALLOW BROWNIES
When it comes to whipping up these fudgy Marshmallow Brownies, the recipe can be broken down into two simple parts: the brownies and the chocolate icing.
MAKE THE BROWNIES
Before you can make the brownie batter, it’s important to line your 8×8″ baking pan with parchment paper, especially if you are making these Marshmallow Brownies for company. You’ll want nice clean-cut brownie squares to impress your guests (but, more on this below)!
USE A PARCHMENT PAPER SLING FOR EASY REMOVAL
To prepare the pan with a parchment paper sling, first grease the pan. Greasing the pan first will help to keep the parchment paper in place. Cut a piece of parchment paper about 8″ wide by about 15″ long.
You want the parchment to hang over the sides so you can use the extra parchment paper as handles to lift the brownies out of the pan.
MIX DRY INGREDIENTS
The brownie batter for this recipe is super easy to make. It begins with a mix of dry ingredients: flour, cocoa powder, baking powder (not to be confused with baking soda), and salt.
Just whisk all of these ingredients together in a small bowl and set the bowl aside while you tend to the wet ingredients.
MIX WET INGREDIENTS
The wet ingredients for these Marshmallow Brownies consists of melted, unsalted butter, eggs, sugar, and vanilla. The first thing you’ll do is break up the eggs by whisking them together in a large mixing bowl.
Then, add the sugar and vanilla and whisk again. Stream in the melted butter, whisking all the while to combine.
Now the dry ingredients go into the wet ingredients. Switching out the whisk for a wooden spoon for this task will be helpful, and you’ll stir until everything is evenly incorporated.
If you’d like to make your brownies extra chocolatey, feel free to add in some chocolate chips! Pour 3/4 cup of semi-sweet chocolate chips into the batter and stir!
BAKE THE BROWNIES
The batter goes into the pan and it’s off to bake at 350°F for about 25 minutes.
ADD THE MARSHMALLOWS
Now for the fun part — that irresistible, ooey-gooey marshmallow layer!
You’ll need an entire package of miniature marshmallows for this. Yes — you read that right. The entire 10-ounce package, which equals about 3 1/2 cups total of miniature marshmallows.
Can you cut back on the amount of marshmallows you add to your Marshmallow Brownies? Absolutely. But, if you want that super-duper high-rise effect, you’ll need to add the whole shebang.
BAKE SOME MORE
Add the marshmallows on top of the almost-baked brownie batter and then return to the oven to bake for another 5 minutes. Once the 5 minutes is up, remove it from the oven and place it on a cooling rack while you make the chocolate icing!
HOW TO MAKE THE CHOCOLATE ICING
The chocolate icing is so, so very simple to make! All you need to do is combine butter, cocoa powder, milk, and salt in a saucepan over medium-high heat and stir until the mixture liquefies.
Then, add in the powdered sugar and stir until smooth. Lastly, add the vanilla, stir, and you’re done!
CAREFUL WHEN YOU POUR! HERE’S WHY:
Note, pour the warm icing slowly across the top of your Marshmallow Brownies, and take care to get good coverage as you pour!
Taking it slowly with the pour matters especially because the top of the chocolate frosting sets quickly and spreading it to the edges with an offset spatula will prove somewhat tricky with that sticky marshmallow on top.
CAN I USE BOX MIX BROWNIES?
If you’re wondering if you can skip out on the made-from-scratch portion of this recipe and use a boxed brownie mix, the answer is yes.
Follow the package instructions to bake your brownies in an 8×8″ baking dish. And, take care to pull the brownies from the oven 5 minutes prior to the end of their cook time to add the marshmallow layer. Then, proceed with the recipe as directed!
HOW TO CUT MARSHMALLOW BROWNIES
You’ll find these brownies are easiest to cut once they’ve completely cooled and the icing is set.
Note, the icing will set before the marshmallow center does, so be sure not to jump the gun on that 2-hour waiting period. You’ll need to wait at least that long before cutting into them. After all, you don’t want to slice into your brownies and have the marshmallow spill out!
If you want to keep the profile of your cut brownies nice, clean, and absolutely beautiful, lift the brownies out of the pan using the parchment paper overhang and transfer to a cutting board or flat work surface.
Then, place a long, sharp, serrated knife over the top of the brownies and press down, cutting the brownies in one overhead, downward movement rather than a sawing motion.
Run the blade of the knife under warm water, carefully wipe it clean, and repeat until you have the desired amount of brownie squares.
HOW MANY SERVINGS DOES THIS RECIPE MAKE?
These brownies are rich…and that’s no understatement, folks. In my standard brownie recipe, I recommend cutting the brownie batch into nine big squares, but because of the full-on decadence that lies within these Marshmallow Brownies, you can absolutely stretch the serving size to feed sixteen!
CAN THESE BROWNIES BE MADE IN ADVANCE?
We could all use a few more make-ahead recipes in our lives, right? This is the ideal make-ahead brownie! Why? The longer you wait, the prettier your cut brownies will be.
If you’re making them for company, consider whipping them up the day before and cutting them the day of.
HOW TO STORE MARSHMALLOW BROWNIES
These brownies maintain their deliciousness integrity for up to 4 days after baking. If you’d like to enjoy them beyond this time period, freeze them!
To freeze these brownies, place them on a flat surface lined with wax paper in your freezer. Once they’re frozen (after a couple of hours), transfer them to a freezer-safe ziptop bag or a freezer-safe storage container and freeze for up to two months.
6 MORE BROWNIE RECIPES YOU’LL LOVE
- S’mores Brownies
- Peanut Butter Brownies
- Walnut Brownies
- Chocolate Chip Brownies
- Red Velvet Brownies
- Brownies With Cream Cheese Frosting
These Marshmallow Brownies are decadent, rich, and oozing with chocolatey, marshmallow goodness. The bottom layer is a soft and chewy, fudgy brownie. Then comes a layer of high-rise, fluffy marshmallow in the center, and a smooth chocolate icing tops it all off!
- 3/4 cup unsalted butter
- 3/4 cup + 2 tablespoons all-purpose flour
- 1/3 cup cocoa powder
- 1 teaspoon baking powder
- 3/4 teaspoon fine sea salt
- 2 large eggs, room temperature
- 1 cup granulated sugar
- 1 teaspoon pure vanilla extract
- 1 package (3 1/2 cups) miniature marshmallows
- 1/2 cup unsalted butter
- 1/3 cup cocoa powder
- 1/3 cup whole milk
- Generous 1/4 teaspoon fine sea salt
- 2 1/2 cups powdered sugar
- 1 teaspoon pure vanilla extract
Preheat the oven to 350°F. Have ready a greased, 8"x8" square baking dish and line with parchment paper, taking care to leave a parchment overhang over the sides.
Melt the butter in a microwave-safe pitcher or bowl, and set aside to cool.
In a medium-sized mixing bowl, combine flour, cocoa powder, baking powder, and salt. Whisk and set aside.
Add the eggs to a large mixing bowl, and whisk. Add the sugar and vanilla, and with a handheld mixer on medium speed (or a sturdy wooden spoon), mix until well combined. Slowly stream in the melted butter, mixing all the while.
Add the dry ingredients and slowly mix until just combined.
Add the batter to baking dish, spread to the edges, and smooth over the top. Bake for 25 minutes, and remove from the oven. Add the marshmallows to the top and return to the oven to bake for 5 minutes more. Once the 5 minutes is up, remove the brownies and set on a cooling rack while you make the icing.
Add the butter, cocoa, milk, and salt to a large saucepan over medium heat and stir. Allow butter to melt, then stir in the powdered sugar, until smooth and add the vanilla.
Slowly drizzle the warm icing evenly over the top of the marshmallow brownies. Allow to set, about 2 hours, before cutting.