Some nights the craving for a s’more shows up at the worst possible time. It is raining, it is cold, and nobody is building a fire out back. These s’mores cookie bars fix that in about forty minutes of kitchen time.
You get the graham, the chocolate, and the marshmallow, all baked into one sliceable bar that actually holds together on a plate.
The layers are easy to picture. A soft, chewy graham cracker cookie dough goes on the top and on the bottom. In between sits a full layer of Hershey’s chocolate bars and a thick spread of marshmallow fluff.
When you cut in, the chocolate has melted into the dough and the fluff stays gooey, stretching just a little as each square lifts out of the pan.
The edges bake up crisp and lightly caramelized while the middle stays soft and gooey. That contrast is the whole point of a s’more. A campfire version is messy and wonderful, but it never travels well. These bars do. They stack, they pack, and they still taste like a night by the fire.
Detail
Info
Prep time
15 minutes
Bake time
25 minutes
Total time
40 minutes
Oven temperature
350F
Pan size
8×8 inch
Servings
16 bars
I started making these after a late summer cookout when my nephew asked for s’mores and the fire had already burned down to nothing. I had graham crackers, chocolate, and a jar of fluff in the pantry, so I turned them into bars instead.
Now they show up at birthday tables, holiday trays, and lunch boxes, and nobody ever asks where the campfire went.
The recipe was built to skip the fire pit, the skewers, and the marshmallows that slide off into the coals. What stays is the combination that made s’mores famous in the first place: graham, chocolate, and marshmallow, with a texture that is crunchy at the edges and gooey in the middle.
There is a reason this pan disappears faster than anything else I bake. These bars are forgiving, familiar, and a little bit showy when you slice them.
S’mores any time of year. An 8×8 pan and a preheated oven are all you need. No campfire, no weather report, no hunting for skewers.
Graham flavor in both layers. The cookie dough itself carries finely crushed graham crackers, so the graham taste runs through every bite instead of sitting on the outside.
A real marshmallow layer. Marshmallow fluff, not mini marshmallows, keeps the center thick and gooey rather than firm.
Clean slices. Once the bars cool, they cut into tidy squares with a neat cross section, which makes them easy to gift, serve at a party, or stack on a platter.
They also taste better on day two and day three, which makes them a smart dessert to bake ahead of time.
Ingredients You’ll Need
Full measurements are in the recipe card below.
The notes here explain what each ingredient is doing, so you know which swaps work and which ones will change the bars.
For the graham cracker cookie dough:
Butter should be softened before you start. Salted or unsalted both work, but if you use unsalted butter, do not skip the added salt. Brown sugar brings chew and a molasses depth, while granulated sugar helps the edges turn crisp.
One large egg holds the dough together, and a full teaspoon of vanilla extract is worth measuring properly instead of eyeballing.
1/2 cup butter, softened
1/3 cup brown sugar
1/4 cup granulated sugar
1 large egg
1 teaspoon vanilla extract
1 1/2 cups all purpose flour
1/2 cup finely crushed graham crackers, about 3 1/2 sheets
1/4 teaspoon salt
3/4 teaspoon baking soda
Measure the flour by spooning it into the cup and leveling it off, or weigh it if you can. About 3 1/2 full sheets of graham crackers, crushed fine, give the dough its s’mores identity, so do not skip them or swap them out for something else. Baking soda adds lift and browning, and the salt keeps everything balanced.
For the s’mores layer:
Five standard Hershey’s chocolate bars go across the middle. Hershey’s is the default for a reason, but any chocolate bar you enjoy works here. Milk chocolate keeps the flavor closest to a classic s’more, while dark chocolate trims the sweetness if the marshmallow fluff feels like a lot.
5 standard Hershey’s bars
1 1/2 cups marshmallow fluff, also called marshmallow creme
Marshmallow fluff is the one ingredient I would not trade out. It stays soft and gooey after baking, which is exactly what mini marshmallows will not do.
How to Make S’mores Cookie Bars
The recipe card has the full step by step method. These are the same steps with the technique notes that make the difference between a good pan and a great one.
Preheat the oven to 350F and line an 8×8 inch baking pan with parchment paper.
Cream the butter with the brown sugar and granulated sugar until combined, then mix in the egg and the vanilla extract.
Add the flour, crushed graham crackers, salt, and baking soda. Mix just until the flour disappears. Overmixing at this stage is what makes cookie bars tough.
Press half the dough evenly into the lined pan, using the bottom of a measuring cup to flatten it. Lift the parchment out with the dough attached and freeze that layer on a baking sheet while you build the rest.
Re line the pan with fresh parchment and press the remaining dough into the bottom.
Lay the chocolate bars over the dough, breaking pieces apart to fill any gaps.
Spread the marshmallow fluff over the chocolate. It does not need to reach the edges, because it spreads as it bakes.
Flip the chilled dough layer on top, using the parchment to guide it into place, then peel the parchment away.
Bake for 25 minutes at 350F, until the top turns golden.
Now the part that tests your patience. Let the bars cool completely before you slice them. Cutting while they are warm means the marshmallow has not set yet, and the clean cross section you were hoping for turns into a sticky pile.
Give them at least 2 hours at room temperature, or 45 minutes in the fridge if you want to speed things along.
Freezing the top dough layer is not a suggestion. It is the reason the bars transfer without tearing and the reason the marshmallow stays inside the pan instead of oozing out.
One bar out of sixteen servings comes in at about 208 calories, with 32g carbohydrates, 3g protein, 8g fat, 5g saturated fat, 1g fiber, 17g sugar, 321mg sodium, and 26mg cholesterol based on the source nutrition.
What Makes These S’mores Bars Different from Traditional S’mores?
A traditional s’more is a roasted marshmallow and a square of chocolate sandwiched between two graham crackers, eaten outdoors with sticky fingers and a little smoke in the air. It is wonderful, and it is gone in three bites.
These bars keep the same four elements: graham, chocolate, marshmallow, and structure. The graham cracker becomes cookie dough, the chocolate becomes a full bar laid across the middle, and the marshmallow becomes fluff that stays gooey after baking. The structure is the new part, and it is what turns a campfire treat into a dessert you can slice.
Element
Classic s’more
S’mores cookie bar
Graham
Two crisp crackers
Graham cracker cookie dough on top and bottom
Chocolate
One square
Five Hershey’s bars in a full layer
Marshmallow
Roasted over a fire
Marshmallow fluff spread in the center
Setting
Campfire, eaten right away
Oven baked, cooled, sliced, and portable
Because they hold together, these bars can go in a lunch bag, ride along to a picnic, or sit on a platter without falling apart. Same flavors, none of the mess.
Tips for Perfect S’mores Cookie Bars
Most problems with cookie bars trace back to one of these five things. Fix them and the pan comes out right every time.
Weigh the flour if you can. One and a half cups can land anywhere between about 180g and 220g depending on how you scoop. Too much flour is the main reason cookie bars turn out dry and cakey.
Do not skip the freezer step. Warm dough tears and stretches when you move it, and the stacked look depends on that chilled layer holding its shape.
Use full size Hershey’s bars, not chocolate chips, in the middle. Chips do not create one continuous melty layer the way whole bars do.
Cool the bars fully before slicing. This is the difference between bars that taste great but look messy and bars that taste great and slice beautifully.
Wipe the knife between cuts. Run a sharp knife under hot water, dry it, slice, wipe, and repeat for clean edges.
Variations and Substitutions
Once the method is familiar, this recipe is friendly to changes. Try one at a time so you can taste what each swap does.
Larger batch. Double everything and bake in a 9×13 pan for 30 to 35 minutes, checking that the top turns golden.
Chocolate choice. Milk chocolate is the classic s’mores option. Dark chocolate cuts the sweetness if the fluff feels heavy. Both work well.
Extra chocolate. Stir chocolate chips into the dough for more chocolate in every bite.
Add crunch. Hershey’s with almonds can stand in for the plain bars. A reader named Luz mentioned this in her review, and it is a good move if you like texture.
Biscoff swap. Replace the crushed graham crackers with crushed Biscoff cookies for a caramelized, cinnamon forward twist.
Peanut butter version. Swirl 2 tablespoons of peanut butter into the marshmallow fluff before spreading it.
How to Store S’mores Cookie Bars
At room temperature, keep the bars in an airtight container for up to 3 days. The marshmallow layer stays gooey the whole time, and honestly the flavor deepens.
In the refrigerator, they keep for up to 1 week in an airtight container. The texture firms up when cold, so let a bar sit at room temperature for about 15 minutes before eating, or microwave it for 10 seconds to bring back that fresh baked feel.
To freeze, wrap individual bars in plastic wrap, slide them into a freezer bag, and freeze for up to 2 months. Thaw at room temperature for a few hours, or microwave for 20 seconds straight from frozen.
For make ahead planning, mix the dough a day ahead and refrigerate it. Let it sit at room temperature for 15 to 20 minutes before pressing it into the pan so it is workable again. That small step means you can bake fresh bars on a busy afternoon without starting from scratch.
FAQs
How do you make s’mores cookie bars?
To make s'mores cookie bars, first cream softened butter with brown sugar and granulated sugar. Mix in an egg and vanilla, then stir in flour, finely crushed graham crackers, baking soda, and salt. Press half the dough into a parchment-lined 8×8 pan, top with 5 standard Hershey's chocolate bars and 1 1/2 cups of marshmallow fluff, then cover with the remaining chilled dough. Bake at 350°F for 25 minutes and cool completely before slicing.
Can I use mini marshmallows instead of marshmallow fluff?
It is not recommended to substitute mini marshmallows for marshmallow fluff. Mini marshmallows re-solidify into a firm, chewy layer when they cool, while marshmallow fluff stays soft and gooey. Using fluff is essential for achieving the characteristic pull-apart center of these bars.
How long do s’mores cookie bars last and how should I store them?
S'mores cookie bars can be stored in an airtight container at room temperature for up to 3 days. They will keep in the refrigerator for up to 1 week and can be frozen for up to 2 months. For the best texture, let refrigerated bars sit at room temperature for 15 minutes before serving, or warm them briefly in the microwave.
Why did my s’mores bars sink in the middle?
S'mores cookie bars typically sink in the middle due to underbaking or slicing into them too early. The bars must bake for the full 25 minutes at 350°F and then cool completely. Allow at least 2 hours at room temperature or 45 minutes in the refrigerator for the marshmallow center to set before cutting, and wipe the knife clean between slices for neat edges.
How do you make s'mores cookie bars?
To make s'mores cookie bars, first cream softened butter with brown sugar and granulated sugar. Mix in an egg and vanilla, then stir in flour, finely crushed graham crackers, baking soda, and salt. Press half the dough into a parchment-lined 8×8 pan, top with 5 standard Hershey's chocolate bars and 1 1/2 cups of marshmallow fluff, then cover with the remaining chilled dough. Bake at 350°F for 25 minutes and cool completely before slicing.
How long do s'mores cookie bars last and how should I store them?
S'mores cookie bars can be stored in an airtight container at room temperature for up to 3 days. They will keep in the refrigerator for up to 1 week and can be frozen for up to 2 months. For the best texture, let refrigerated bars sit at room temperature for 15 minutes before serving, or warm them briefly in the microwave.
S’mores Cookie Bars Some nights the craving for a s’more shows up at the worst possible time. It is raining, it is cold, and nobody is building a fire out back.
Ingredients
Scale
Cookie dough 1/2 cup Butter, softened, salted or unsalted 1/3 cup brown sugar 1/4 cup granulated sugar 1 egg 1 tsp vanilla extract 1 & 1/2 cup AP flour 1/2 cup graham crackers, finely crushed, about 3.5 sheets 1/4 tsp salt 3/4 tsp baking soda 5 standard Hershey bars 1 & 1/2 cup Marshmallow fluff
Instructions
1-Preheat the oven to 350F then line: Preheat the oven to 350F then line an 8×8 inch baking pan with parchment paper and set it aside. 2-Cream the butter, granulated sugar, and brown: Cream the butter, granulated sugar, and brown sugar until combined. Add in the egg and the vanilla extract and mix again. 3-Add in the flour, graham cracker crumbs,: Add in the flour, graham cracker crumbs, salt, baking soda, and mix just until the flour mixture disappears. 4-Press half of the dough evenly onto: Press half of the dough evenly onto the prepared baking sheet then remove that parchment from the pan and place in the freezer while you re-line the pan with more parchment paper and repeat the process with the leftover cookie dough. 5-Place the chocolate bars over the dough,: Place the chocolate bars over the dough, feel free to break pieces apart to fit the whole surface. Spread the marshmallow fluff or creme on top of the chocolate bar then gently flip the chilled cookie dough layer on top working carefully to keep it intact. 6-Bake the cookies in the preheated oven: Bake the cookies in the preheated oven for 25 minutes. Make sure you let the bars cool down fully before slicing into them to get that beautiful cross section that you see in my images.
