These s’mores brownies are the perfect sweet treat for Summer BBQs and picnics. They bake up in a 9×13-inch sheet pan, so they feed a crowd. With a graham-cracker-studded, fudgy chocolate brownie, topped with melted marshmallows, Hershey milk chocolate pieces and graham cracker crumbs.
S’mores brownies: at a glance
What are they? Moist and fudgy, semi-sweet brownies with crumbled graham crackers stirred into the batter, and baked with jumbo marshmallows on top. After baking, pieces of Hershey’s milk chocolate are placed on top, and crushed graham cracker crumbs are scattered over the top.
Why you’ll love them! These brownies bake up in a 9×13-inch sheet pan or baking pan, and can be cut to yield 24 servings, so they are great for feeding a crowd. And speaking of crowd, s’mores treats are always a crowd-pleaser. They can be made a day ahead, if needed, and they travel well. They also freeze well!
How do you make them? You’ll need just a bowl and a spoon to mix up the brownie batter. Once mixed, stir some crumbled graham crackers through the batter. Bake the brownies for about 12 minutes, then add the marshmallows. Return to the oven for another 10-12 minutes to finish baking. Once out of the oven, sprinkle with crushed graham crackers and top with a few pieces of Hershey’s milk chocolate.
Love s’mores flavours without the campfire? You might like to try my S’mores-stuffed Chocolate Chip Cookies or my S’mores Cookie Bars next!
Ingredients and substitutions
A few notes about the key ingredients …
Semi-sweet chocolate – I tested these brownies with dark chocolate and found them a little too rich for a true “s’mores” experience. Semi-sweet chocolate was much nicer for these brownies. I recommend the bars of semi-sweet baking chocolate (such as Baker’s brand), rather than chocolate chips, though semi-sweet chocolate chips will work here. Note that you will need two boxes of Baker’s semi-sweet baking chocolate, as you will need 10oz in total, and the boxes here are just 8 oz. In a pinch, you can use one box and top up with semi-sweet chocolate chips if you like.
Cake flour – Cake flour is recommended if you have it on hand. If not, I’ve included a quick DIY cake flour substitute using all-purpose flour and cornstarch. It’s noted in the Notes section of the Recipe Card below.
Jumbo marshmallows – I tested this recipe with regular-sized marshmallows, and they will work (with an adjustment to the timing of when they are put on top of the brownies). I preferred to use the “Jumbo” Jet-Puffed brand marshmallows, as the slightly bigger size cooked more slowly and was less likely to overcook. I know there are some really huge marshmallows available. The really big marshmallows can be used, but I would cut them in half before using.
Graham crackers – Be sure to buy the actual crackers and not the graham crumbs.
Hershey’s milk chocolate bar – It just wouldn’t be s’mores without some Hershey’s milk chocolate! You’ll just need one small Hershey’s bar.
How to make s’mores brownies: step-by-step
This is a visual summary of the steps to make this recipe. Scroll down to the Recipe Card below for the complete list of ingredients and instructions.
Step 1: Start by melting together the chocolate and butter in a large saucepan.
Step 2: Add the white sugar to the melted chocolate and butter.
Step 3: Add the brown sugar to the batter.
Step 4: Sift the flour and cocoa powder into the batter and fold in.
Step 5: Stir the crumbled graham crackers into the brownie batter.
Step 6: Pour the batter into a 9×13-inch pan and bake for about 12 minutes.
Step 7: Remove from the oven and place the marshmallows on top of the partially-baked brownies. Return to the oven to bake another 12 minutes.
Step 8: Bake until the brownies are done and the marshmallows are golden and still a little gooey. Top with Hershey’s milk chocolate pieces and crushed graham crackers.
Recipe tips!
- Note that I used a ceramic 9×13-inch baker’s slab here, which may bake a little faster (or slower) than a metal 9×13-inch pan. Be sure to watch closely after about 20 minutes of baking!
- You can use a 9×13-inch rimmed baking sheet or a 9x-13-inch glass or metal cake pan. Baking time will vary depending on whether you use glass or metal.
- Test the brownies by inserting a tester into the centre of the pan, avoiding the marshmallow. The tester should come out with a few moist crumbs (not dry or not liquid-y). Avoid over-baking so you don’t end up with dry brownies.
- If somehow your brownies were baked before the marshmallows were nicely golden, switch the oven to broil briefly to brown them a bit more. Watch closely as they can quickly burn!
- You can sprinkle the graham cracker crumbs on the brownies as soon as they come out of the oven, but wait 5-10 minutes before adding the Hershey’s milk chocolate so they don’t completely melt. If you have room in the fridge, I like to pop the whole pan into the fridge once they’ve cooled a bit to stiffen up the chocolate and brownies, for easier cutting into squares.
- I didn’t have any issue getting the brownies out of the pan (sprayed with baking spray), but if you want to be sure they come out of the pan neatly, line the bottom and sides of the pan with parchment paper and grease the parchment as well.
Top tip!
The goal with these s’mores brownies is not to melt the marshmallows completely, or they just become kind of gummy marshmallow splats on top of the brownies. Instead, we want the marshmallows well-browned, but with still a bit of gooey marshmallow goodness.
To accomplish that, you’ll need to put the marshmallows on top of the brownies partway through baking. I found halfway through worked perfectly with the Jumbo marshmallows. If using regular-sized marshmallows, you’ll want to put them on a bit later in the baking process. If you have those huge marshmallows, I suggest cutting them in half, so they will be closer to the Jumbo-sized ones.
Making ahead, storing and freezing
These brownies can be made 24 hours ahead, though they are probably at their absolute best if enjoyed the same day they are baked.
As noted above, I like to chill the brownies for easier cutting into squares, but that said, you don’t want to store the brownies or they may dry out. If you are making a day ahead, take them out of the fridge, wrap well, and just store at room temperature. You can pop them into the fridge for an hour before slicing, if you like.
These brownies will freeze well for up to 2 months.
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Get the Recipe: S’mores Brownies
Ingredients
- 1 cup (226 g) unsalted butter, can substitute salted butter, but reduce the added salt below
- 10 oz (283 g) semi-sweet chocolate, chopped *see Note 1 below
- 1 cup (200 g) white granulated sugar
- 3/4 cup (135 g) light brown sugar, well-packed
- 4 large eggs, at room temperature
- 2 teaspoons vanilla extract
- 1 teaspoon kosher salt, reduce to 1/2 teaspoon if using salted butter
- 1 1/3 cups (155 g) cake flour, stirred, spoon and levelled *see Note 2 below
- 5 Tablespoons natural cocoa powder
- 8-10 graham cracker squares, hand-crumbled *see Note 3 below
- 14-15 jumbo Jet-Puffed marshmallows, *see Note 4 below
For topping after baking:
- 1/3 cup graham cracker squares, crushed
- 8-10 pieces Hershey's milk chocolate bar, separated into individual pieces
Instructions
- Preheat the oven to 350F (regular bake setting/not convection or fan-assisted) with the oven rack in the middle. Generously butter or spray a 9×13-inch baking pan or dish.
- In a large saucepan, melt the 1 cup unsalted butter (can substitute salted butter, but reduce the added salt below) and 10 oz semi-sweet chocolate (chopped *see Note 1 below) over low heat, stirring regularly. Remove the saucepan from the heat and whisk in the 1 cup white granulated sugar and 3/4 cup light brown sugar (well-packed). Allow the mixture to cool for a few minutes, stirring a couple of times, then whisk in the 4 large eggs (at room temperature), one at a time, beating well after each addition. Stir in the 2 teaspoons vanilla extract and 1 teaspoon kosher salt (reduce to 1/2 teaspoon if using salted butter).
- Using a fine sieve, sift the 1 1/3 cups cake flour (stirred, spoon and levelled *see Note 2 below) and 5 Tablespoons natural cocoa powder over the chocolate mixture and use a rubber spatula to stir in just until blended. Stir in the 8-10 graham cracker squares (hand-crumbled *see Note 3 below). Pour the brownie batter into the prepared pan and spread evenly.
- Bake the brownies for 12 minutes (bake for 14 minutes if using regular-sized marshmallows), then remove the pan from the oven and add the 14-15 jumbo Jet-Puffed marshmallows (*see Note 4 below) to the top of the partially-baked brownies, pressing them into the brownies a bit.
- Return the brownies to the oven and bake until the brownies are baked and the marshmallows are golden, but still a little gooey, about 8-12 minutes more.
- Remove from the oven and sprinkle the 1/3 cup graham cracker squares (crushed) over the brownies. Let the brownies stand for 5-10 minutes, then place the 8-10 pieces Hershey's milk chocolate bar (separated into individual pieces) randomly on the top.
- Allow to cool completely before slicing. (I like to pop the brownies into the fridge briefly to set the Hershey's pieces, which will soften from the heat of the brownies and to make the brownies easier to cut.)
Notes
More s’mores-inspired recipes to love!
Hi! I’m Jennifer, a home cook schooled by trial and error and almost 40 years of getting dinner on the table! I love to share my favourite recipes, both old and new, together with lots of tips and tricks to hopefully help make your home cooking enjoyable, stress-free, rewarding and of course, delicious!
