Mississippi Mud Brownies

Mississippi mud brownies are all about layers. A fudgy brownie base, a blanket of gooey marshmallow creme, and a river of melted chocolate frosting swirled through the top. It looks like a mess and tastes like a dream.

This version keeps things smart by starting with a boxed brownie mix. No shame in that shortcut when the real magic happens on top. The marshmallow creme goes on while the brownies are still screaming hot from the oven, which is the key move. That heat softens the creme so it spreads into a thin, sticky layer without tearing the brownie surface.

Then the melted frosting gets poured right over and swirled with a knife. You’re going for a marble effect, not a full blend. Those distinct ribbons of chocolate and marshmallow are what make this look as wild as it tastes.

Let them cool completely before cutting. Patience is hard here, but warm mud brownies will stick to everything and fall apart. Once set, they slice cleanly into rich, layered bars with that signature pull of marshmallow in every bite.

Pro Tips

• Spread the marshmallow creme immediately after pulling brownies from the oven; it won’t spread on a cooled surface
• Microwave the frosting for 30 seconds to get it pourable, but don’t overheat or it gets too thin
• Use a butter knife in long, sweeping strokes for the marble; too much swirling muddies the layers
• Cut with a wet knife to get clean slices through the sticky marshmallow layer

Variations

• Pecan mud: Press chopped pecans into the marshmallow layer before adding frosting for a classic Southern touch
• Peanut butter swirl: Add spoonfuls of warmed peanut butter alongside the chocolate frosting before marbling
• S’mores style: Use graham cracker crumbs in the brownie batter for a campfire twist