Anything Mississippi Mud is a winner in my book. If you aren’t familiar, it is basically rocky road, minus the nuts. So fudgy goodness with gooey marshmallow and more chocolate.
In the case of Mississippi Mud Brownies, this means using an easy boxed brownie mix, topped with a layer of marshmallow fluff and then chocolate ganache and more marshmallows. They are rich, decadent and always a crowd-pleaser.
And the best part about using a box mix? This Mississippi Mud Brownie recipe uses less than ten ingredients to take a regular brownie and turn it into a sweet treat that will be enjoyed by all. With flavors reminiscent of a Mississippi mud cake, it’s quickly become a favorite recipe of mine.
How to Cleanly Cut Brownies
We’ve all been there. A beautiful tray of brownies and now we need to slice them without totally destroying them. Cutting brownies neatly isn’t a skill, it just requires the right tools. Here are a few tips on how to cleanly cut brownies.
- Wait until brownies are cooled. If you have the time, you can also chill them.
- Use a plastic knife. Plastic doesn’t stick as much.
- Run a metal knife under hot water, repeat after each slice.
- Spray the knife with cooking spray.
- Clean the knife after each slice.
Mississippi Mud Brownies Ingredients
- Box brownie mix – We’re stepping up a regular box mix with some extra ingredients. Don’t forget you’ll also need the ingredients required on the back of the box to make them. These are usually large eggs and vegetable oil.
- Marshmallow fluff – That fluffy marshmallow layer on top of the brownies is made from melted marshmallow fluff.
- Butter – We use unsalted melted butter to blend with the cocoa powder to make the most delicious ganache layer to top the pan of brownies. We use this instead of chocolate icing because it has a richer chocolate flavor.
- Unsweetened cocoa powder – To make these rich brownies even richer, we use cocoa powder to make our chocolate ganache instead of chocolate chips.
- Heavy whipping cream – We need something to help thin out our ganache, and heavy cream does just that. It makes it extra creamy as well.
- Salt – We use unsalted butter for these Mississippi Mud Brownies so that I can control the amount of salt in the recipe. I prefer using fine sea salt when baking.
- Powdered sugar – Because we use unsweetened cocoa powder, we need an element of sweet for our ganache. Powdered sugar ensures that it stays nice and smooth.
- Mini marshmallows – I like to top my brownies with even more fluffy marshmallows. Not only do they taste great, but they give your brownies a fun look too.
How to Make Mississippi Mud Brownies
- Prepare oven and pan. Preheat the oven according to the package directions for the brownie mix. Coat your pan with cooking spray or parchment paper.
- Make brownie layer. Prepare the brownie batter according to package directions. Pour batter into pan and bake.
- Marshmallow layer. While brownies are still warm, place marshmallow fluff in a microwave-safe bowl or glass measuring bowl. Heat in intervals until melted. Pour over warm brownies, spreading out evenly using an offset spatula.
- Make ganache. In a large bowl beat together the melted butter, cocoa powder, heavy cream and salt until combined. Add the powdered sugar slowly so the mixture is still pourable, but starts to have a little body and texture. Pour over the marshmallow layer, spreading out with an offset spatula.
- Add marshmallows. While the chocolate ganache layer is still tacky, sprinkle mini marshmallows and gently press to adhere. Allow them to fully cool to room temperature before cutting.
I love making mine into a sundae with whipped cream (sometimes even chocolate whipped cream) and a cherry on top.
Storage and Freezing
Store this Mississippi Mud Brownies recipe in an airtight container. Due to the ganache layer, they will need to be refrigerated. They will be good for up to five days total.
You can freeze these moist brownie for up to three months. These are best enjoyed at room temperature (no one likes cold brownies!) so allow them to come up to room temp to enjoy any leftovers.
More Bar Recipes
Mississippi Mud Brownies
- 18.3 ounce box brownie mix plus ingredients to make them
- 2 cups marshmallow fluff
- 1/2 cup unsalted butter melted
- 1/3 cup unsweetened cocoa powder
- 1/3 cup heavy cream
- 1/4 teaspoon fine sea salt
- 4 cups powdered sugar
- 1/4 cup mini marshmallows cut in half
- Preheat the oven according to the package directions for the brownie mix. Coat a 9×13 pan with cooking spray or parchment paper.
- Prepare brownies according to package directions. Remove and set aside.
- While brownies are still warm, place marshmallow fluff in a microwave-safe bowl or glass measuring bowl. Heat for 30 seconds on high heat, stir. If not smooth, return for another 30 seconds and then stir again.
- Pour over warm brownies, spreading out evenly using an offset spatula. Set aside.
- In the bowl of a stand mixer fitted with a paddle attachment or a large mixing bowl with an electric hand mixer, beat together the melted butter, cocoa powder, heavy cream and salt until combined.
- Add the powdered sugar slowly so the mixture is still pourable, but starts to have a little body and texture.
- Pour over the marshmallow layer, spreading out with an offset spatula.
- While the chocolate ganache layer is still tacky, sprinkle mini marshmallows and gently press to adhere. Allow them to fully cool.
- Cut brownies into squares.
- If you’ve tried this recipe, come back and let us know how it was in the comment or star ratings!