Gooey S'mores Brownies
Fudgy, gooey brownies with a graham cracker crust and a gooey toasted marshmallow topping. This simple recipe is one of your favorite treats—turned s’mores!
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Why this recipe works
First, the brownies. Because we’re using so little flour, it’s okay to use just butter in these brownies. It gives just enough fluff to help them rise but also plenty of moisture to keep these soft for days. Also, melting the butter before mixing with the sugar helps dissolve the sugar before baking. Sugar turns liquid when heated, so you want it melted before baking if possible, to help the brownies come together. We’re also going to bake these just until set. They’ll be fudgy and chewy but still sliceable. And finally, extra chocolate chips. You’re going to measure with your heart here—but don’t get crazy. One cup or so of chocolate chips is perfect. Or less. Or none. Follow your chocolate loving heart here.
All that’s needed from there to make these s’mores brownies is to add some graham crackers and toasted marshmallows. So, I simply lined the pan with an easy graham cracker crust then topped the finished brownies with mini marshmallows, letting them brown for a few minutes on the top rack of my oven. Not only was all this simple, but it gave these such a perfect s’mores flavor and just the right amount of ooey gooey goodness. S’mores, but make them brownies.
Key ingredients
Flour. Be sure to spoon then level the flour so you don’t have too much.
Cocoa powder. Use unsweetened cocoa, and do not skip the sifting!
Baking powder. Use fresh baking powder, meaning not opened longer than 6 months.
Salt. Sea salt is ideal.
Butter. European butter is best, as it has less water. You’ll use some in the brownies and some in the graham cracker crust.
Sugar. Use granulated sugar. Again, most of this is for the brownies, but a little goes into the graham cracker crust.
Eggs. Use fresh, large, room temperature eggs.
Vanilla extract. Use pure extract, not imitation.
Chocolate Chips. You can use any size and flavor you’d like! I used semisweet.
Graham crackers. Obviously! You can use any kind you prefer for a classic s’mores taste.
Mini marshmallows. You could use regular, but that might get too gooey (if there is such a thing?). You could also cut regular sized marshmallows in half and stick them cut-side-down on the brownies.
How to make gooey s’mores brownies
1. Grind graham crackers and sugar.
2. Add melted butter.
3. Press crust into your pan. At this point, pre-baking the crust on its own is optional. I prefer leaving it alone and letting it bake with the brownie batter on top, so the two melt into each other.
4. Sift and whisk the flour, cocoa, baking powder, and salt.
5. Melt the butter.
6. Whisk still-hot butter into the sugar. Whisk for a good minute or so to help it begin to dissolve.
7. Add the eggs and vanilla, one at a time. Whisk about a minute after each egg. Add the vanilla and whisk well again.
8. Gently fold in dry ingredients. Leave some streaks of flour.
9. Fold in the chocolate chips. This step should take care of the remaining streaks of cocoa and flour.
10. Pour on top of graham cracker crust and bake. Brownies are done when the top is no longer shiny and the middle is slightly jiggly but not liquidy. You can also use a toothpick, but most people like it when about half of the toothpick comes out with some doughy (not raw) batter on it.
11. Top with marshmallows and bake or broil until golden. I just set these on the top rack of my oven for less than 5 minutes, letting them puff up and turn golden. However, you could broil or torch the marshmallows instead, especially if you’re wanting to ensure the brownies stay nice and gooey and don’t over bake.
Enjoy!
Tips and FAQ’s for this recipe
Can I just use plain graham crackers?
Yes! I’ve seen recipes that simply line a pan with graham crackers and then pour brownie batter on top. However, I’ve also eaten brownies made this way and the graham crackers turned soggy. I like that this method retains that graham cracker crunch, so I went with an actual crust that wouldn’t turn soggy. A little bit did crumble when I cut these, but pouring the batter on top of the unbaked crust seemed to make a difference, allowing them to bake together and create fewer crumbs.
What kind of marshmallows are best?
Personally, I liked using mini marshmallows. It was less messy than fluff and added the perfect amount of marshmallows. However, you’re welcome to use regular! You can leave them as-is or cut them in half (I recommend adding them cut-side-down for best baking). It’s entirely up to you and your personal preference. I liked that I could create one tight layer of mini marshmallows with little to no gaps, meaning every square inch of these brownies was covered in gooey marshmallow.
Can I use salted butter?
Yes, but you probably won’t need any salt in that case. It really depends on the brand. I often use Kerrygold salted butter and only add a pinch of salt for a double recipe of frosting, so taste as you go and use your better judgment on adding additional salt.
Use quality cocoa
Since cocoa is the main flavor here, you want a good brand. Opt for something organic and fair trade, if possible, because this usually means it was produced in smaller batches and thus higher quality and is often fresher, too. Plus, the flavor of the high quality cocoa is always noticeable in the brownies. My go-to is Volupta, from Costco, but some other good options are Ghirardelli, Guittard, Scharffen Berger, Anthony’s, or even Hershey’s Special Dark in a pinch.
Sift your dry ingredients
Usually, you don’t need to sift the dry ingredients unless it’s cake. However, I realized that every time I tried making brownies, my cocoa left little clumps that in turn caused me to over mix my batter. Instead, sifting the dry ingredients means you can simply fold them into the wet ingredients without over mixing, resulting in a tender, fudgy brownie that’s not dense.
Whisk sugar well
The idea is to dissolve the sugar quite a bit. It turns to liquid in the oven, so you want it liquid before the baking so it can absorb into the flour and cocoa. Something magical happens in this process, making a super fudgy brownie.
Measure the chocolate chips with your heart
I was telling my best friend about some amazing cookies I’d just made and that it was crazy how easy the recipe was. Of course, I always use extra chocolate chips. And she said one of my favorite quotes I’ve ever heard: chocolate chips should be measured with the heart. And it’s true. I always measure out what the recipe calls for then pour a little extra for good measure. But two notes: 1) this only works for mix-in chocolate chips, like in cookies and brownies, not ganache or things like these dark chocolate cupcakes, and 2) there is a point where you’ve added so many chocolate chips that they’re literally drowning out the batter or dough. As long as you keep those in mind, follow your heart.
My tools
Here are my must-have tools I use for making these brownies. Affiliate links provided.
Fine mesh sieve (because sifting is KEY)
All-rubber spatula (this makes scraping the bowl easier so the batter doesn’t get all over a wooden handle!)
Mini serving spatula (weird, but I LOVE this for bars and brownies!)
Stand mixer or handheld mixer (for the buttercream)
Gooey S’mores Brownies
- prep time: 15-20 minutes
- bake time: 20-25 minutes
- total time: 45 minutes
servings: 12-16 (double recipe for a 9x13 with 12 large, bakery style brownies!)
Ingredients:
for the graham cracker crust
- 10 full graham crackers (about 150g)
- 4 tablespoons(50g) granulated sugar
- 6 tablespoons (85g) unsalted butter, melted
for the brownies
- ½ cup (68g) all-purpose flour
- ⅔ cup (53g) unsweetened cocoa powder
- ½ teaspoon (2g) baking powder
- ¼ teaspoon (2g) sea salt (or ½ teaspoon (3g) table salt)
- ½ cup (113g) unsalted butter*
- 1 ¼ cups (250g) granulated sugar
- 2 large eggs
- 1 tablespoon (13g) pure vanilla extract
- 1 cup (170g) chocolate chips (or as many as your heart says you need)
- about 1 ½ cups (340g) mini marshmallows
Instructions:
- Preheat oven to 350F/175C. Grease an 8x8 square pan with butter and flour or baking spray.
- Place graham crackers and sugar in a food processor or blender. Grind until the size of cornmeal (ish—there’s a point where it just doesn’t get finer unless you grind it for a few minutes).
- Add the melted butter. You can combine both in a mixing bowl or save some dishes and just add the butter to the processor or blender and pulse a few times, stir as best you can, then pulse a few more times. You’ll also want to stir it a bit when you turn it out into the baking pan if you use this method.
- Pour crust into prepared pan. Spread evenly then press crust into pan with a spatula or the bottom of a cup. Note: you don’t have to use all of the crust–it’s up to personal preference.
- Next, make the brownie batter. Using a fine mesh sieve set over a small mixing bowl, sift then whisk together the flour, cocoa powder, baking powder, and salt. Set aside.
- In a small saucepan, melt the butter until completely liquid. Immediately combine it with the sugar in a large mixing bowl and whisk for about a minute, until it comes together and the sugar begins to dissolve.
- Add the eggs, one at a time, whisking for about a minute after each egg. Add the vanilla and whisk well again (half a minute should do this time).
- Add the dry ingredients in and gently fold in with a wooden spoon or rubber spatula, until almost blended some streaks of flour remain.
- Gently fold in the chocolate chips.
- Pour gently on top of graham cracker crust, smoothing the top and getting the batter mostly into the corners (I like to leave a ½ inch gap that will absolutely fill in during baking but prevent an overly crunchy corner).
- Bake for 20-25 minutes, or until the top is no longer shiny/raw looking and the middle is slightly jiggly but not liquidy. A toothpick should actually come out with some matte-looking batter (not quite raw dough, not quite crumbly brownies). If you prefer fully cooked, non-fudgy-middle brownies, cook a little longer until a toothpick comes out with several brownie crumbs rather than a smear of almost-cooked batter.
- Immediately** add marshmallows on top of brownies. Spread in an even layer. Either brown with a kitchen torch, return to the oven on the top rack for 3-4 minutes, or broil for 1-2 minutes, until marshmallows puff up and turn golden.
- Let cool in pan at least 30 minutes (or serve right away with a fork!).
Enjoy!
Brownies will last in an airtight container at room temperature for 3-5 days, if you can resist eating them all before then!
*European butter is best! It has less water and makes a better brownie, in my opinion.
**You can optionally wait until serving to toast the marshmallows, but they may not adhere as well to the cooled brownies.