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These s’mores brownies with box mix are the dessert I make when I want that campfire flavor without the campfire. A box of brownie mix gets doctored up until it tastes better than from-scratch, then it bakes right on top of a layer of graham crackers and gets crowned with toasted mini marshmallows. You get the fudgy chocolate, the crunch, and the gooey toasted top in one pan, any time of year.
Since you are here, make sure to take a look at my 10 secrets to make brownie mix better, these brownie mix cookies, as well as these lazy girl pumpkin cheesecake brownies.
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Every summer the s’mores craving hits before I have anywhere to actually build a fire. One year it was 108 degrees outside in Vegas and the last thing I wanted was to stand over an open flame, but I still wanted that toasted-marshmallow-and-chocolate thing so badly. So I did what I always do and figured out how to get it out of my own oven.
Layering the brownie batter straight onto graham crackers gave me the crust without a separate step, and broiling the marshmallows at the end got them that bonfire-char without anyone getting near a fire. Now this is the version I come back to all summer, and honestly all winter too when the craving shows up out of season.
Why this is the best easy s’mores brownie recipe
These homemade s’mores brownies are one of those desserts you don’t think about until you’ve had them once, and then you want them on repeat. Starting with brownie mix saves you time without sacrificing anything, because a few simple swaps make the box taste like a from-scratch batch. You get a fudgy, rich brownie, a built-in graham cracker crust, and a toasted marshmallow top, all from one easy recipe.
Why you need to make this recipe
- Quick and easy. The box mix does the heavy lifting, so these come together fast.
- The best texture combo. Fudgy brownie, crunchy graham cracker bottom, and ooey gooey toasted marshmallow in every bite.
- Crowd pleaser. Perfect for a potluck, a BBQ, or anytime you need a dessert that disappears fast.
- Beginner friendly. Simple ingredients and no fussy steps. The hardest part is waiting for them to cool before slicing.
- Better than the box. A handful of easy upgrades (egg yolks, coffee, a little extra chocolate) make these taste homemade.
Ingredients for these delicious s’mores brownies
Here are the ingredients you will need to make this s’mores brownies recipe. Make sure to scroll down to the recipe card for the full detailed ingredient measurements.
- Brownie mix – A higher-quality box mix makes a noticeable difference in the final taste. Use one sized for an 8×8 inch pan.
- Egg yolks – I use yolks instead of whole eggs to make these extra fudgy and rich. You can use whole eggs if that’s what you have.
- Vegetable oil or butter – Oil keeps things easy, but melted butter makes them even richer.
- Coffee – Freshly brewed coffee deepens the chocolate flavor. Swap in hot water if you’d rather skip it.
- Vanilla extract
- Salt
- Chocolate chips – Semisweet or milk chocolate both work.
- Graham crackers – Whole sheets to line the bottom for that built-in s’mores crust.
- Mini marshmallows – These bring the whole dessert together.
- Nonstick cooking spray – My trick for slicing. It keeps the marshmallows from sticking to the knife.
How to make these s’mores fudgy brownies
Here’s how to make s’mores brownies with box mix. Scroll down to the recipe card for the full detailed instructions.
- Preheat the oven to 325F and line an 8×8 inch pan with parchment paper, leaving an overhang on the sides for easy lifting later.
- Layer the graham cracker sheets across the bottom of the pan in a single layer, breaking some to fit so they cover the whole surface.
- In a large bowl, mix the brownie mix, egg yolks, hot brewed coffee, oil, vanilla, and salt until a thick batter forms. Fold in the chocolate chips.
- Pour the batter evenly over the graham crackers and spread into an even layer. Bake for 40 minutes.
- Pull the brownies out and top with the mini marshmallows. Return to the oven for another 3 to 4 minutes.
- Using a kitchen torch or the broiler, toast the marshmallows until golden. Watch closely so they don’t burn.
- Let the brownies cool fully before slicing. Spray your knife with nonstick spray for clean cuts.
- Slice and enjoy your toasty s’mores brownies.
How to make s’mores brownies in a 9×13 pan
This recipe is written for an 8×8 inch pan, which makes 16 squares. If you need a crowd-size batch, double everything and bake it in a 9×13 pan. Here is how to scale it:
- Double the brownie mix (use two boxes, or one large family-size box meant for a 9×13), the egg yolks, oil, coffee, vanilla, salt, and chocolate chips.
- Use about 8 to 9 graham cracker sheets to cover the bottom of the 9×13 in a single layer.
- Bake at the same 325F, but add roughly 8 to 12 minutes to the bake time. Start checking at the original time plus 8 minutes and look for set edges with a fudgy center.
- Top with 3 to 4 cups of mini marshmallows and toast as usual.
Pro tip: A 9×13 is roughly double the area of an 8×8, so doubling the recipe is the cleanest scale. Keep the oven temp the same and judge doneness by the center, not just the clock.
Frequently asked questions – FAQ
Yes. Instead of a separate pressed crust, you line the bottom of the pan with whole graham cracker sheets and pour the brownie batter right on top. As it bakes, the grahams soften slightly into a built-in crust layer, which is the easiest way to get that s’mores base without any extra steps.
You can. Use your favorite homemade brownie batter for an 8×8 pan, then build it exactly the same way: graham crackers on the bottom, batter on top, marshmallows broiled at the end. The box mix version is here because it is faster and foolproof, but the assembly is identical either way.
Any 8×8 size box mix works, but a higher quality mix gives you a richer result. Whichever you grab, the egg yolks, brewed coffee, and extra chocolate chips in this recipe are what take it from basic box to bakery good.
You can store these brownies in an airtight container for up to 4 days. Just remember that the longer they sit the softer the graham cracker bottom will become softer.
Feel free to toast these again before serving or warm them up in the microwave for a more ooey gooey melty experience.
The best way to have the perfect slices for brownies in general is to allow them to cool down fully before slicing.
But for this specific recipe, we will have to add an additional step because of the marshmallow layer. Make sure to spray your knife with nonstick spray or any oil before slicing so that you avoid pulling the gooey marshmallows with the knife.
This will yield beautiful brownie squares that are almost too pretty to eat.
Lazy girl s’mores brownies
Ingredients
- 5 graham cracker sheets
- 1 box of brownie mix for an 8×8 inch pan
- 2 egg yolk
- 1/2 cup vegetable oil or melted butter
- 1/3 cup brewed hot coffee
- 1 tsp vanilla extract
- 1/4 tsp salt
- 1/2 cup chocolate chips
- 2 cups mini marshmallows
Instructions
- Preheat the oven 325F then line the bottom of an 8×8 inch baking pan with parchment paper or aluminum foil, leaving an overhang on the sides for easy removal later.
- Place the graham cracker sheets on the bottom of the pan in a single layer, covering the entire surface. You may need to break some of the sheets to fit them evenly.5 graham cracker sheets
- In a large bowl, mix the brownie mix, egg yolks, hot brewest coffee, vegetable oil, vanilla extract, and salt. Fold in the chocolate chips.1 box of brownie mix, 2 egg yolk, 1/2 cup vegetable oil, 1/3 cup brewed hot coffee, 1 tsp vanilla extract, 1/4 tsp salt, 1/2 cup chocolate chips
- Pour the brownie batter evenly over the layer of graham crackers in the prepared pan then bake in the preheated oven for 40 minutes.
- Pull the brownies out and carefully top them with the mini marshmallows. Place back in the oven and bake for another 3-4 minutes.2 cups mini marshmallows
- Remove the pan from the oven then using a kitchen torch, toast the marshmallows on top. Allow the brownies to cool down fully before slicing and enjoying. Read the notes on how to slice this dessert.
How to toast marshmallows without a kitchen torch?
- If you don't have a kitchen torch, place the pan with the marshmallows under the broiler and keep a close eye on it. Toast the marshmallows until they turn golden brown, but be careful not to let them burn. This should only take a few minutes, so stay nearby to monitor the process.
- Once the marshmallows are toasted to your liking, remove the pan from the oven and let it cool completely.
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
