There are brownies… and then there are the kind you cut into while they’re still warm and immediately understand why waiting was never going to happen.
These Gooey S’mores Lava Brownies combine a rich fudgy brownie base with melted chocolate, toasted marshmallow, and that unmistakable graham cracker flavor inspired by classic campfire s’mores.
The edges stay slightly chewy, the middle stays soft and almost molten, and the marshmallow topping melts into every chocolatey bite.
They’re messy, rich, and completely over-the-top in the best way.
Perfect for weekend baking, birthday desserts, summer gatherings, movie nights, or any day that needs more chocolate.
Why You’ll Love These Gooey S’mores Lava Brownies
These brownies are all about texture.
You get a dense, fudgy chocolate brownie on the bottom, a warm chocolate lava layer hidden inside, soft marshmallows melting across the top, and buttery graham cracker pieces adding just enough crunch.
The combination tastes familiar like the s’mores you grew up making, but the brownie base turns everything into a much richer dessert.
And if you serve them slightly warm?
That molten chocolate center is hard to beat.
What You’ll Need
For the Fudgy Brownies
- 1 cup unsalted butter
- 8 ounces semi-sweet chocolate, chopped
- 1½ cups granulated sugar
- ½ cup brown sugar
- 4 large eggs
- 2 teaspoons vanilla extract
- 1 cup all-purpose flour
- ¾ cup unsweetened cocoa powder
- ½ teaspoon salt
For the Chocolate Lava Center
- 1 cup semi-sweet chocolate chips
- ½ cup heavy cream
For the S’mores Topping
- 2 cups mini marshmallows
- 1 cup roughly crushed graham crackers
- ½ cup chocolate chunks or chips
- Extra graham cracker crumbs for finishing
How to Make Gooey S’mores Lava Brownies
Preheat your oven to 350°F and line a 9×9-inch baking pan with parchment paper.
Start by melting the butter and chopped chocolate together until completely smooth.
Let the mixture cool for a few minutes.
Whisk in both sugars, then add the eggs one at a time. Stir in the vanilla.
In another bowl, whisk together the flour, cocoa powder, and salt.
Gently fold the dry ingredients into the chocolate mixture just until combined. Avoid overmixing if you want that dense, fudgy center.
Pour about half of the brownie batter into the prepared pan.
For the lava filling, heat the heavy cream until hot but not boiling, then pour it over the chocolate chips.
Let it sit for about two minutes before stirring until smooth and glossy.
Spoon the chocolate mixture over the brownie batter, leaving a small border around the edges.
Cover gently with the remaining brownie batter.
Bake for about 25 to 30 minutes, until the edges look set but the middle remains soft.
Remove the brownies from the oven and immediately scatter mini marshmallows, chocolate chunks, and broken graham crackers across the top.
Return the pan to the oven for another 3 to 5 minutes, just until the marshmallows puff and soften.
For a lightly toasted finish, broil them very briefly while watching closely.
Let the brownies rest for about 15 to 20 minutes before slicing.
The Best Part
The real magic happens when you cut through the center while the brownies are still slightly warm.
The top gives you soft toasted marshmallow and crunchy graham cracker pieces.
Then your fork reaches that rich brownie layer.
And finally, the chocolate center slowly spreads out into a thick, glossy ribbon.
It’s basically a campfire s’more that decided it wanted to become the most dramatic brownie on the table.
A Little Note From My Kitchen
These are definitely not the brownies I bake when I want perfectly neat little squares.
I actually love them slightly messy.
The marshmallow stretches, the chocolate melts into the plate, and little graham cracker crumbs end up everywhere.
That’s part of the fun.
Sometimes I tuck extra chocolate squares into the center before baking when I know I want that really dramatic molten effect.
And if I’m serving them for dessert, a scoop of vanilla ice cream on a warm brownie is almost unfairly good.
Would you eat yours straight from the pan or add the ice cream too?
More desserts you’ll love
If you love gooey chocolate desserts like these Gooey S’mores Lava Brownies, try Brownie Batter Cinnamon Rolls for another ultra-rich treat packed with warm chocolate swirls. For a classic celebration cake, Better Than Bakery Chocolate Cake delivers deep chocolate flavor and an incredibly moist crumb. If molten centers are your weakness, Chocolate Lava Pancake Pillows hide warm chocolate inside fluffy pancakes, while Brookie Cheesecake Stuffed Bombs combine cookie, brownie, and cheesecake in one bite. You can also try Marshmallow Chocolate Chip Cloud Cookies for that stretchy marshmallow moment, or Triple Chocolate Fudge Layer Cake when only an extra-rich chocolate dessert will do.
Quick Tips
How do I keep the brownies gooey?
Avoid overbaking. The center should still look slightly soft when you remove the pan from the oven.
Can I make them ahead?
Yes. Bake them ahead and gently reheat individual portions before serving to bring back the soft chocolate center.
Can I use large marshmallows?
Absolutely. Cut them into smaller pieces so they melt evenly across the brownies.
How should I store leftovers?
Store them covered at room temperature for up to two days or refrigerate for longer storage.
Easy Variation
Turn these into peanut butter s’mores brownies by spreading a thin layer of creamy peanut butter over the chocolate lava filling before covering it with the remaining brownie batter.
You can also use chocolate graham crackers for an even deeper chocolate flavor.
