The brownie + marshmallows + toasted pecans + fudge sauce combo has never been tastier (or easier!). These Mississippi Mud Bars are insanely delicious and so simple to make!

Ingredients You Will Need

For the Brownie Base

• Butter: 1 cup, unsalted and melted.
• Sugar: 2 cups granulated white sugar.
• Cocoa Powder: 1/2 cup, high-quality unsweetened.
• Eggs: 4 large eggs.
• Vanilla Extract: 2 teaspoons.
• Flour: 1 ½ cups all-purpose.
• Salt: 1/2 teaspoon.

For the Toppings

• Marshmallows: 4 cups miniature marshmallows.
• Pecans: 1 ½ cups, roughly chopped and lightly toasted in a dry pan.
• Fudge Sauce: 1 cup semi-sweet chocolate chips melted with 1/2 cup butter and a splash of heavy cream for that perfect pourable consistency.

Preparation Method

1. Bake the Base: Preheat your oven to 350°F (175°C) and grease a 9×13 inch baking pan. In a large bowl, whisk together the melted butter, sugar, and cocoa powder. Add the eggs one at a time, beating well after each addition, then stir in the vanilla. Gradually fold in the flour and salt until just combined. Pour the batter into the prepared pan and bake for 25–30 minutes, or until a toothpick inserted into the center comes out with a few moist crumbs.
2. The Marshmallow Layer: Immediately upon removing the brownies from the oven, spread the miniature marshmallows evenly over the top. Return the pan to the oven for 3–5 minutes. You are not trying to melt them into a puddle, but rather soften them until they are puffy and starting to turn a light golden color.
3. The Crunch: While the marshmallows are still warm and sticky, sprinkle the toasted pecans evenly over the top. Press them down very gently with the back of a spoon to ensure they adhere to the marshmallow layer.
4. The Finishing Sauce: In a small saucepan, melt the chocolate chips, butter, and cream together over low heat until smooth and glossy. Drizzle this rich fudge sauce liberally across the entire pan, ensuring it drips into the gaps between the pecans and marshmallows.

Serving and Storage

For the best experience, allow the bars to cool completely at room temperature before attempting to cut them. Because of the marshmallow and fudge layers, they are best served as “bars,” which can be achieved by using a sharp knife sprayed with a little non-stick cooking spray to prevent sticking.

Store these in an airtight container at room temperature for up to three days, though, in most households, they disappear long before that. If you want to elevate them even further, serve each square slightly warmed with a cold glass of milk or a simple scoop of vanilla bean ice cream to balance the intensity of the fudge. It is, quite simply, the ultimate summer-to-winter bridge dessert.