These S'mores Brownies will bring that classic campfire flavor to your kitchen! These decadent brownies have a brown butter graham cracker base, a rich and fudgy chocolate brownie, and are topped with toasted marshmallow fluff! They're full of nostalgic - yet elevated - s'mores flavor!
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These brownies are the ULTIMATE summer dessert! No need to pack your bags and get a fire going, we're re-creating that classic s'mores flavor in brownie form at home and it's incredible.
There are a few steps to make these perfect, but we promise it's worth the effort!
Looking for more brownie recipes to try? Check out our loaded brownies, these chocolate cherry brownies, these red velvet brownies, or this brownie skillet!
Love marshmallows? Try our chocolate chip and marshmallow cookies!
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❤️Why We Love This Recipe
- Decadent, nostalgic flavors. If you're craving s'mores and want a little extra something - these brownies are IT!
- Crowd pleaser. Our taste testers (aka our friends and family) RAVED about how delicious these brownies were. Take them to your next BBQ, potluck, or cookout, and everyone will love them!
- Made with simple ingredients. Everything you need to make these brownies can be found at any grocery store if you don't already have everything you need at home!
🍫Ingredients
Here are the ingredients we used for this recipe. You can find more information for substitutions below.
- Chocolate bar. We opted for bittersweet chocolate here, but semi-sweet and dark also work. We recommend using a bar and cutting it up so that it melts down nicely. You can also use chocolate chips if you prefer.
- Cocoa powder. We tend to opt for Dutch-processed cocoa powder, which is treated with alkaline to lessen its acidity. This makes it darker in color and smooth tasting, with a less bitter flavor. With that said, any cocoa powder will work for this recipe!
- Espresso powder. Technically optional, but will really deepen the chocolate flavor and enhance the brownie!
- Marshmallow fluff. If you want to make your own, go for it! We just like the stuff in the tubs for ease. Plus, it tastes great!
Visit the recipe card for the full quantities and nutritional information.
✨Substitutions & Variations
Here are a few suggestions on additional flavors to try, or simple variations to this recipe.
- No marshmallow fluff. You can make your own, or just swap it for whole marshmallows!
- Easier crust. Swap the graham cracker crust for whole sheets of graham crackers. It will still be tasty, although, not AS tasty 😉 but will still work! If you go this route, just place them on the bottom of the baking pan, pour the brownie batter over top, and then bake.
- Box mix brownies. This is another easy shortcut you could use. Simply use your favorite box mix, and follow the instructions on the box. Although, we do recommend adding vanilla, espresso powder, milk instead of water, and butter instead of oil. 😉
- Gluten-free. To make this recipe gluten-free (it should work well!!) swap the all-purpose flour for your favorite gluten-free flour, and use gluten-free graham crackers!
This recipe hasn't been tested with any other substitutions or variations, so we can't guarantee any results. If you make a change, let us know how it goes in the comments below!
🔪Prep Work
- Allow the eggs to sit out at room temperature for about an hour.
- Preheat the oven to 350°F.
- Grease the bottom of an 8x8-inch pan and line it with parchment paper.
- Chop the chocolate bar into small pieces.
- Measure out the rest of the ingredients using a food scale.
📋Instructions
Prep the ingredients
Place cocoa powder, the chopped chocolate bar, and optional espresso powder in a small bowl or beaker. Set aside. (Image 1)
Next, brown or heat your butter. Here is our step-by-step guide on how to brown butter.
The key is, whether you're browning the butter or not, the butter needs to be hot enough to melt the chocolate easily!
Separate the browned butter for the crust in a medium-sized bowl. Set aside to cool. (Image 2)
Pour the remaining hot butter over the top of the chocolate and cocoa powder mixture and mix to melt the chocolate. (Image 3) Set aside to cool.
⭑Pro tip: We want the butter to be hot to melt the chocolate, and activate the cocoa powder and espresso powder to deepen the chocolate flavor.
Graham cracker crust
In a bowl, mix the brown butter, brown sugar, vanilla extract, and egg yolk together. (Image 4)
Using a food processor or just a rolling pin and bag, make graham cracker crumbs. (Image 5)
Add the graham cracker crumbs, all purpose flour, and salt to the wet ingredients. (Image 6) Mix to combine, it will have a sand-like texture that clumps together slightly.
⭑Pro tip: We don't want the butter to be too hot, or it will make the crust greasy. Allow it to cool off for 5-10 minutes before adding the sugar, egg yolk, and vanilla.
Press the crust into the pan in an even layer using a cup or just your hands. Use a fork to poke holes all over the bottom of the crust. (Image 7)
Bake for 12-15 minutes until the crust is golden brown and set. Place on a cooling rack while you work on the brownie filling. (Image 8)
Brownie layer
In a mixing bowl, mix together the brown sugar, eggs, and egg yolk (Image 9) until pale and fluffy. Next, add in the vanilla extract, then, stream in the cooled chocolate, cocoa powder, butter, and espresso powder mixture until completely combined. (Image 10)
Add in the all purpose flour and salt, (Image 11) and switch to a rubber spatula to gently mix.
Once the dry ingredients are almost all the way combined (there will still be a few streaks of flour), fold in the chocolate chunks or chips. (Image 12)
⭑Pro tip: Once the dry ingredients are added, don't overmix, or the brownies will become chewy and tough! Mix until just combined, and stop!
Assemble and bake
Pour the brownie batter over top of the graham cracker crust, and spread it evenly with an offset spatula. (Image 13)
Bake for roughly 30-35 minutes, testing for doneness by inserting a toothpick into the center of the brownies beginning at 30 minutes.
You’ll know they’re done when the edges are set, but a toothpick comes out with a few moist crumbs on the toothpick. (Image 14) Set aside to cool for about 45 minutes to an hour.
⭑Pro tip: Make sure to let your brownies cool completely. We know it's hard to wait! Because we underbake the brownies, we need time to allow them to finish cooking in the pan or they will still be a bit too raw in the center.
Marshmallow topping
Once the brownies have cooled off, preheat the broiler to high.
Spread the marshmallow fluff over top of the brownies using an offset spatula. It may pull up some of the crumbs from the brownies, but that's okay. (Image 15)
Place under the broiler for 3-5 minutes, watching VERY CAREFULLY to prevent the marshmallows from burning. TRUST US, it goes very quickly!
When the top is nice and golden brown, set it aside to cool for about 15-20 minutes before cutting in! (Image 16) This allows the topping a bit of time to set up.
⭑Pro tip: You can use a blow torch, but we prefer to use the broiler method so that the topping puffs up a little taller, and the top is more evenly toasted. Please note that if you use a blow torch instead, it won't puff up as tall.
Now, all that's left to do is cut these brownies into 12-16 equal pieces.
⭑Pro tip: Use a sharp knife that's been run under hot water. You can also oil the knife between each pass to prevent the marshmallows from sticking to the knife and create nice clean layers!
✨Top Tips
- Use a kitchen scale for best results. This is probably our top tip, every time! Using a kitchen scale makes all the difference for accurate measurements, and brownies with a perfect texture!
- Room-temperature ingredients. Use room-temperature eggs. This helps them incorporate smoothly into the batter, instead of causing the batter to seize up.
- Let the chocolate and butter mixture cool off before adding it to the batter, or you might accidentally scramble your eggs!
- Don't overmix the flour. Mix until just combined, and then stop! Overmixing can lead to a tough, unpleasant texture in the brownie.
- Use an oven thermometer. Be aware of your oven's actual temperature! Some ovens run hotter or cooler than the temperature dial states. We love using an oven thermometer to verify the actual temperature.
- Don't overbake and experiment with baking time. If you like gooier brownies, bake for a shorter time. For cake-like brownies, bake a bit longer. Personally, we always recommend underbaking a little bit, because we love an ooey-gooey brownie!
- Cool completely. Allow the brownies to cool completely in the pan. Patience is key because they need time to finish cooking. Also, the marshmallow topping will set up better if it has a moment to sit.
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💭Frequently Asked Questions
Store leftovers in an airtight container at room temperature for up to 5-6 days. To freeze, wrap tightly in plastic wrap, then aluminum foil, and place in the freezer for up to 3 months.
You probably used too much flour, to fix this, next time use a digital food scale to measure accurately. If you don't have a scale, fluff the flour and spoon it into a measuring cup, and don't pack it tight. Then, use a knife to level off the excess on top.
Another reason your brownies could be dry is you baked them too long. Brownies need a lot of time to cool and set up, so it's good to underbake them since they will continue cooking in the pan!
You probably overmixed the batter after adding the flour. Overworking the flour will result in too much gluten production, making your brownies tough. Simply mix until everything is completely incorporated, then stop! We like to switch to a rubber spatula when adding in the dry ingredients to make sure we don't mix too much.
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📖 Recipe
S'mores Brownies Recipe
Equipment
- hand mixer (or a whisk, or a stand mixer with a whisk attachment)
Ingredients
Brown butter
- 3 sticks unsalted butter (24 tablespoons. When browning butter, the amount reduces by about 20-25% due to water evaporating, so we start with more than we will actually need. Please see notes.*)
Graham cracker crust
- 6.5 tablespoons brown butter, melted and slightly cooled 91g (can sub regular melted unsalted butter)
- 9 tablespoons brown sugar 113g
- 1 large egg yolk room temperature
- 2.5 teaspoons vanilla extract
- ¾ cup all purpose flour 90g
- ¾ cup graham cracker crumbs (about 1 sleeve of Graham crackers) 90g
- ¾ teaspoon kosher salt
Brownies
- 12.5 tablespoons brown butter, hot 182g (can sub regular melted unsalted butter, must be HOT!)
- 3 ounces bittersweet or dark chocolate bar 85g, chopped
- ⅓ cup cocoa powder 30g (Dutch-processed if possible)
- 1 ¼ cups brown sugar 250g
- 2 teaspoons instant espresso optional
- 2 large eggs room temperature
- 1 large egg yolk room temperature
- 1 teaspoon kosher salt
- 1 tablespoon vanilla extract
- ¾ cup all-purpose flour 90g
- ½ cup chocolate chunks semi-sweet, bittersweet, or dark 70g, optional
Marshmallow fluff topping
- 7.5 ounces marshmallow creme 1 container
Instructions
- Preheat the oven to 350°F. Grease the bottom of an 8x8-inch pan and line it with parchment paper.
Brown butter
- Optional step. Skip if not browning the butter. Your butter does need to be hot either way. In a small saucepan, brown the butter. When the butter is a golden amber color and gives off a nutty aroma, remove it from the heat and weigh it using a food scale. It should weigh about 273 grams (or the equivalent of about 19 tablespoons). This is because some of it will evaporate when cooking.3 sticks unsalted butter
- Set about 91g (6.5 tablespoons) aside for the graham cracker crust. Let it cool.
- Take the remaining 182 grams (about 13 tablespoons) of hot butter and pour it directly over chopped chocolate, cocoa powder, and optional espresso powder in a container. Stir to melt the chocolate completely. Set aside to cool.3 ounces bittersweet or dark chocolate bar, ⅓ cup cocoa powder, 2 teaspoons instant espresso, 12.5 tablespoons brown butter, hot
Graham cracker crust
- In a mixing bowl, mix brown butter, brown sugar, vanilla extract, and the egg yolk together until smooth and combined.6.5 tablespoons brown butter, melted and slightly cooled, 9 tablespoons brown sugar, 2.5 teaspoons vanilla extract, 1 large egg yolk
- Add the graham cracker crumbs, all purpose flour, and salt to the wet ingredients. Mix to combine, it will have a sand-like texture that clumps together slightly.¾ cup all purpose flour, ¾ cup graham cracker crumbs, ¾ teaspoon kosher salt
- Press the crust into the pan in an even layer using a cup or just your hands. Use a fork to poke holes all over the bottom of the crust. Bake for 12-15 minutes until the crust is golden brown and set. Place on a cooling rack while you work on the brownie filling.
Brownies
- In a mixing bowl, mix together the brown sugar, eggs, and egg yolk until pale and fluffy. Next, add in the vanilla extract, then, stream in the cooled chocolate, cocoa powder, butter, and espresso powder mixture until completely combined.1 ¼ cups brown sugar, 2 large eggs, 1 large egg yolk, 1 tablespoon vanilla extract
- Add in the all purpose flour and salt, and switch to a rubber spatula to gently mix. Once the dry ingredients are almost all the way combined (there will still be a few streaks of flour), fold in the chocolate chunks or chips.1 teaspoon kosher salt, ¾ cup all-purpose flour, ½ cup chocolate chunks
Assemble and bake
- Pour the brownie batter over top of the graham cracker crust, and spread it evenly with an offset spatula.
- Bake for roughly 30-35 minutes, testing for doneness by inserting a toothpick into the center of the brownies beginning at 30 minutes. You’ll know they’re done when the edges are set, but a toothpick comes out with a few moist crumbs on the toothpick. Set aside to cool for about 45 minutes to an hour.
Toasted marshmallow topping
- Once the brownies have cooled off, preheat the broiler to high. Spread the marshmallow fluff over top of the brownies using an offset spatula.7.5 ounces marshmallow creme
- Place under the broiler for 3-5 minutes, watching VERY CAREFULLY to prevent the marshmallows from burning. TRUST US, it goes very quickly!
- When the top is nice and golden brown, set it aside to cool for about 15-20 minutes before cutting in! This allows the topping a bit of time to set up.
Serve
- Now, all that's left to do is cut these brownies into 12-16 equal pieces and enjoy!
- Store leftovers in an airtight container at room temperature for up to 5-6 days. To freeze, wrap tightly in plastic wrap, then aluminum foil, and place in the freezer for up to 3 months
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Video
Notes
- You can use a blow torch, but we prefer to use the broiler method so that the topping puffs up a little taller, and the top is more evenly toasted. Please note that if you use a blow torch instead, it won't puff up as tall.
- Use a kitchen scale for best results.
- Use room-temperature eggs to help them incorporate smoothly into the batter, instead of causing the batter to seize up.
- Let the chocolate and butter mixture cool off before adding it to the batter, or you might accidentally scramble your eggs!
- Don't overmix the flour. Mix until just combined, and then stop! Overmixing can lead to a tough brownie.
- Use an oven thermometer. Be aware of your oven's actual temperature, because it may not be quite accurate. Use a thermometer to be sure.
- Don't overbake. If you like gooier brownies, bake for a shorter time. We always recommend underbaking a little bit, because we love an ooey-gooey brownie!
- Cool completely. Allow the brownies to cool completely in the pan. Patience is key because they need time to finish cooking. Also, the marshmallow topping will set up better if it has a moment to sit.
Kayla says
These are some of the most delicious brownies I've ever had!! Thank you for sharing such a wonderful recipe 😋
Briana says
I'm so glad you enjoyed them so much Kayla!! Grateful for this feedback!!