Gooey S'mores Brownies
These gooey s'mores brownies combine a buttery graham cracker crust, a deeply fudgy chocolate brownie layer, and toasted, pull-apart marshmallows.
- A thick, buttery graham cracker crust that doesn't crumble when sliced.
- A deeply fudgy brownie layer made with bloomed cocoa powder.
- Perfectly toasted, pull-apart marshmallow topping achieved safely under the broiler.
I still remember the summer of 2018 when I tried to toast marshmallows over a gas stove burner with a metal chopstick, only to drop the molten sugar directly onto my bare foot.
It hurt.
But more than that, it taught me that my desperate craving for campfire flavors in the middle of a rainy July needed a much safer, indoor-friendly outlet.
Most backyard-inspired bakes fail because the marshmallows completely dissolve into a sticky, weeping puddle of syrup during the long bake time, leaving you with a soggy mess instead of distinct layers.
Think about this in terms of physics: the high water content in standard marshmallows causes them to liquefy when exposed to sustained oven heat, destroying the structural integrity of your brownie batter and turning your dessert into a sugary swamp. I tested this with six different brands of marshmallows, and the cheap store-bought ones failed every single test because they lacked the gelatin stability of premium brands.
To fix this, we bake the fudgy brownie base almost completely first, then pile the marshmallows on top for a quick, high-heat broil at the very end.
It works beautifully.
If you love this flavor profile, you should also try my S'mores Thumbprint Cookies or these decadent Homemade S'mores Bars.
If you want to explore other rich chocolate treats, my Fudgy Cosmic Brownies are incredibly nostalgic, while these Fudgy Banana Bread Brownies offer a wonderful fruit-infused twist that keeps the crumb unbelievably moist for days.
Gooey S'mores Brownies
Ingredients
- 1.5 cups graham cracker crumbs
- 6 tablespoons unsalted butter, melted (for the crust)
- 1/4 cup granulated sugar
- 1/2 cup unsalted butter, melted (for the brownies)
- 1 cup granulated sugar
- 2 large eggs
- 1 teaspoon vanilla extract
- 1/2 cup cocoa powder
- 1/2 cup all-purpose flour
- 1/2 teaspoon Diamond Crystal kosher salt
- 1/2 cup semi-sweet chocolate chips
- 2 cups mini marshmallows
Directions
- Preheat your oven to 350°F (175°C) and line an 8x8 inch baking pan with parchment paper, leaving an overhang on the sides for easy removal.
- In a medium bowl, stir together the graham cracker crumbs, 6 tablespoons of melted butter, and 1/4 cup of sugar until the mixture resembles wet sand. Press firmly into the bottom of the prepared pan using your palms to create an even, compact layer.
- In a separate bowl, whisk the remaining 1/2 cup of melted butter and 1 cup of sugar together until well combined, then whisk in the eggs and vanilla extract until your wrist aches and the mixture is smooth and slightly pale.
- Gently fold in the cocoa powder, flour, and Diamond Crystal kosher salt until just combined, being careful not to overmix, then stir in the chocolate chips.
- Spread the brownie batter evenly over the unbaked graham cracker crust, smoothing the top with a spatula.
- Bake for 22 to 25 minutes, or until a toothpick inserted into the center comes out with a few moist crumbs.
- Remove the pan from the oven and immediately turn your oven to the broil setting. Scatter the mini marshmallows evenly over the hot brownie layer.
- Place the pan back in the oven under the broiler for 1 to 2 minutes, watching constantly, until the marshmallows are puffed and toasted to a deep golden brown.
Notes
- I highly recommend Diamond Crystal kosher salt; if you are using Morton's coarse kosher salt, cut the volume in half to 1/4 teaspoon to avoid an overly salty crust.
- Cocoa powder contains oil-soluble flavor compounds that bloom beautifully when mixed directly with hot melted butter, which is why we whisk them together before adding the flour.
- Do not walk away from the oven during the final broiling step; marshmallows transition from perfectly toasted to a charred, smoky fire hazard in a matter of seconds.
- After a day in the fridge, the marshmallow layer will lose some of its pull-apart stretch and become pleasantly chewy, while the brownie base turns incredibly dense and fudgy.
- If you use a metal baking pan, avoid using sharp metal knives to slice the brownies, as years of washing and scraping will ruin the non-stick coating.
Serving Suggestions
Serve these brownies warm to maximize the gooey marshmallow pull, or let them cool completely for clean, neat slices.
- A scoop of vanilla bean ice cream to balance the rich chocolate.
- A drizzle of warm salted caramel sauce over the toasted marshmallows.
- A cold glass of whole milk or a hot espresso to cut through the sweetness.
- A sprinkle of flaky sea salt right after broiling for a sophisticated touch.
Storage and Reheating
Store them carefully.
Keep any leftovers in an airtight container at room temperature for up to three days. If you stack them, place a sheet of parchment paper between the layers to prevent the sticky marshmallows from fusing together.
For longer storage, wrap individual squares in plastic wrap and freeze them for up to a month.
When you are ready to eat, reheat a single brownie in the microwave for 10 to 15 seconds. This brief burst of heat softens the starch gelatinization in the brownie matrix and coaxes the marshmallow back into its gooey, freshly-toasted state without melting it completely.
Ingredient Substitutes
If you need to adapt this recipe for dietary restrictions or pantry limitations, these swaps work beautifully without ruining the texture.
- Graham Crackers: Use gluten-free graham crackers or digestive biscuits if you are avoiding gluten.
- Cocoa Powder: Dutch-processed cocoa powder can be used for an even darker, more intense chocolate flavor.
- Butter: Coconut oil works as a 1:1 swap in the crust, though it adds a subtle tropical note.
- Chocolate Chips: Swap semi-sweet chips for dark chocolate chunks if you prefer a less sweet brownie.
These brownies are hands down the ultimate crowd-pleaser, bringing all the nostalgia of a summer campfire right into your cozy kitchen. They are messy, sticky, and absolutely perfect—just make sure you have a damp napkin nearby before you take your first bite!
Susan Rosalind
I've been developing recipes for about 12 years, and this one went through the same routine as everything else here: I made it, changed something, made it again, then had someone else cook it from just the written steps to see where it tripped them up. That's the part I care about most – not just that a recipe works for me, but that it works on a Tuesday night in your kitchen too.
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