Mississippi Mud Brownies

Last week, we were in the mood for brownies. We were in the mood for brownies with “stuff”. Not just any old plain brownie, but brownies filled, topped and layered with ingredients. It then dawned on us that even though we had made Mississippi Mud Cake a little over a year ago, we had never made the brownie version, which we've been meaning to do since we made the cake. We had everything we needed for the brownies, which was all the encouragement we needed. As we all know, there’s never a bad time for a brownie!
Much like the cake version, these Mississippi Mud Brownies are rich, chewy brownies that are topped with marshmallows, covered in a fabulous chocolate fudge icing and sprinkled with chopped pecans. We took the blow torch to the marshmallows before covering them in the icing, which gives the brownies a faint toasted flavor. It’s reliable if you love s’mores! (If not, you can totally skip that step and it won’t negatively affect the brownies.) we can’t resist chocolate and marshmallows together, so these brownies are right up our alley.
What’s your favorite way to jazz up plain brownies?
Two years ago: Chocolate Chip Cookie Dough Brownies and Everything Bagels
Three years ago: From-scratch Pop-Tarts
Four years ago: Anise-Almond Biscotti and Better-than-Brownies Chocolate Cookies
Mississippi Mud Brownies
Yield: 12 brownies Fudgy brownies topped with toasted marshmallows, fudge icing and chopped pecans.For the Brownies:
- ½ cup (62.5 g) all-purpose flour
- ½ cup (43 g) unsweetened cocoa powder
- ¾ cup (150 g) granulated sugar
- ⅓ cup (66.67 g) packed light-brown sugar
- ¼ teaspoon (0.25 teaspoon) salt
- ½ cup (113.5 g) unsalted butter, melted and cooled slightly
- 2 eggs
- 1 teaspoon vanilla extract
- ¾ cup (74.25 g) chopped pecans, divided
- 2½ cups (187.5 g) miniature marshmallows
For the Fudge Icing:
- ¼ cup (56.75 g) unsalted butter
- ¼ cup (61 ml) whole milk
- ¼ cup (21.5 g) unsweetened cocoa powder
- ½ teaspoon (0.5 teaspoon) vanilla extract
- 2 cups (240 g) powdered sugar
- Pinch of salt
- Make the Brownies: Preheat oven to 325 degrees F. Line an 8x8-inch square baking dish with aluminum foil and coat lightly with non-stick cooking spray.
- In a large bowl, whisk together the flour, cocoa powder, granulated sugar, brown sugar and salt until blended. Using a wooden spoon, stir in the melted butter and mix until combined. (The batter may get hard like fudge at this point.) Add the eggs and vanilla extract and stir until blended and no clumps remain. Fold in ½ cup of the chopped pecans. Pour the batter into the prepared baking dish and bake for 35 - 37 minutes, or until a thin knife or skewer inserted into the center comes out with plush crumbs attached.
- Remove from the oven and sprinkle the marshmallows evenly over the top. Return the pan to the oven and bake until the marshmallows are slightly puffy, about 4 minutes. Remove from oven and place on a wire cooling rack. Allow the brownies to rest for 5 minutes, then toast the tops of marshmallows with a kitchen torch (this is optional).
- Make the Chocolate Fudge Icing: In a small saucepan, melt the butter over medium-high heat, stirring frequently. Add the milk and cocoa powder and cook, whisking constantly, until the mixture has thickened, 1 to 2 minutes. Remove from the heat and add the powdered sugar, vanilla and salt, and beat with an electric mixer on medium speed until the frosting is smooth.
- Immediately pour and spread the chocolate icing evenly over top (work quickly as the icing begins to harden as soon as it's made). Sprinkle the top with the remaining chopped pecans. Allow to cool completely and cut into squares. The brownies can be stored in an airtight container at room temperature for up to 5 days.
Notes
Nutritional values are based on one serving

- Yield: 12 brownies
- Prep: 25 minutes
- Cook: 35 minutes
- Total: 1 hour
Ingredients
For the Brownies:
- ½ cup ( 62.5 g ) all-purpose flour
- ½ cup ( 43 g ) unsweetened cocoa powder
- ¾ cup ( 150 g ) granulated sugar
- ⅓ cup ( 66.67 g ) packed light-brown sugar
- ¼ teaspoon ( 0.25 teaspoon ) salt
- ½ cup ( 113.5 g ) unsalted butter, melted and cooled slightly
- 2 eggs
- 1 teaspoon vanilla extract
- ¾ cup ( 74.25 g ) chopped pecans, divided
- 2½ cups ( 187.5 g ) miniature marshmallows
For the Fudge Icing:
- ¼ cup ( 56.75 g ) unsalted butter
- ¼ cup ( 61 ml ) whole milk
- ¼ cup ( 21.5 g ) unsweetened cocoa powder
- ½ teaspoon ( 0.5 teaspoon ) vanilla extract
- 2 cups ( 240 g ) powdered sugar
- Pinch of salt
Method
- Make the Brownies: Preheat oven to 325 degrees F. Line an 8x8-inch square baking dish with aluminum foil and coat lightly with non-stick cooking spray.
- In a large bowl, whisk together the flour, cocoa powder, granulated sugar, brown sugar and salt until blended. Using a wooden spoon, stir in the melted butter and mix until combined. (The batter may get hard like fudge at this point.) Add the eggs and vanilla extract and stir until blended and no clumps remain. Fold in ½ cup of the chopped pecans. Pour the batter into the prepared baking dish and bake for 35 - 37 minutes, or until a thin knife or skewer inserted into the center comes out with plush crumbs attached.
- Remove from the oven and sprinkle the marshmallows evenly over the top. Return the pan to the oven and bake until the marshmallows are slightly puffy, about 4 minutes. Remove from oven and place on a wire cooling rack. Allow the brownies to rest for 5 minutes, then toast the tops of marshmallows with a kitchen torch (this is optional).
- Make the Chocolate Fudge Icing: In a small saucepan, melt the butter over medium-high heat, stirring frequently. Add the milk and cocoa powder and cook, whisking constantly, until the mixture has thickened, 1 to 2 minutes. Remove from the heat and add the powdered sugar, vanilla and salt, and beat with an electric mixer on medium speed until the frosting is smooth.
- Immediately pour and spread the chocolate icing evenly over top (work quickly as the icing begins to harden as soon as it's made). Sprinkle the top with the remaining chopped pecans. Allow to cool completely and cut into squares. The brownies can be stored in an airtight container at room temperature for up to 5 days.








