Dessert

Ultimate Mississippi Mud Brownies That Melt in Your Mouth Recipe

ByZoe Lane February 19, 2026February 19, 2026

Introduction

These Ultimate Mississippi Mud Brownies are rich, gooey, and melt in your mouth with every bite. Topped with a layer of mini marshmallows and a creamy chocolate frosting, they make the perfect indulgent treat for any chocolate lover.

A close-up of a three-layer chocolate dessert slice on a wooden board with a white marbled texture background, the bottom layer is dark, dense, and moist chocolate cake, the middle layer is a creamy, rich, milk chocolate mousse with a smooth texture, and the top layer is a thick, white whipped cream topped with dark chocolate curls scattered unevenly, with a small drop of chocolate sauce on the board near the dessert, photo taken with an iphone --ar 4:5 --v 7

Ingredients

1 cup unsweetened cocoa powder
1/2 cup oil
1/2 cup butter (softened, unsalted recommended)
1 cup granulated sugar
4 large eggs
1 teaspoon vanilla extract
1 cup all-purpose flour
1/2 teaspoon salt
2 cups mini marshmallows
1/2 cup melted butter (for frosting)
1/4 cup unsweetened cocoa powder (for frosting)
1/4 cup evaporated milk
1 teaspoon vanilla extract (for frosting)
3 cups powdered sugar

Instructions

Step 1: Preheat your oven to 350°F and grease a 9×13-inch pan with non-stick cooking spray.
Step 2: In a large mixing bowl, whisk together the oil and 1 cup cocoa powder until smooth.
Step 3: Add the softened butter and blend until creamy, then mix in the granulated sugar.
Step 4: Add eggs one at a time, mixing well after each addition, then stir in 1 teaspoon vanilla extract.
Step 5: Gently fold in the flour and salt, taking care not to overmix the batter.
Step 6: Pour the batter into the prepared pan and bake for 25 to 30 minutes until a toothpick inserted near the center comes out with moist crumbs.
Step 7: Remove brownies from the oven and evenly sprinkle mini marshmallows on top. Return to oven for 2 to 3 minutes to melt the marshmallows.
Step 8: Allow the brownies to cool completely in the pan before frosting.
Step 9: To make the frosting, mix melted butter, 1/4 cup cocoa powder, evaporated milk, and 2 cups powdered sugar in a bowl until smooth.
Step 10: Gradually add the remaining powdered sugar until the frosting reaches your desired thickness.
Step 11: Stir in 1 teaspoon vanilla extract, then spread the frosting evenly over the cooled brownies.
Step 12: Cut into squares and serve.

Tips & Variations

For extra gooey brownies, try adding a handful of chocolate chips to the batter before baking.
If you prefer a thicker frosting, add more powdered sugar gradually until you reach the desired consistency.
You can substitute mini marshmallows with regular marshmallows cut into smaller pieces.

Storage

Store brownies in an airtight container at room temperature for up to 3 days. For longer storage, refrigerate for up to a week or freeze for up to 3 months. When reheating, warm in the microwave for 15-20 seconds to soften the frosting and marshmallows.

How to Serve

A close-up of a square piece of layered chocolate dessert on a wooden surface with a small pool of chocolate sauce in front. The dessert has four distinct layers: the bottom layer is dense, dark, and moist chocolate cake; above it is a thick, smooth layer of darker chocolate fudge; next is a lighter, airy chocolate cake layer; and the top is a thick, creamy white layer of frosting covered with irregular dark chocolate curls. Some chocolate drizzle is visible on the creamy top edges. The background is softly blurred with a white marbled texture surface. photo taken with an iphone --ar 4:5 --v 7

Serve this delicious recipe with your favorite sides.

FAQs

Can I use salted butter instead of unsalted?

Yes, you can use salted butter, but reduce or omit any added salt in the recipe to avoid over-salting.

How do I know when the brownies are done?

The brownies are done when a toothpick inserted in the center comes out with a few moist crumbs but no raw batter. Avoid overbaking to keep them fudgy.