Chocolate Chip Marshmallow Cookie Bars

Chocolate Chip Marshmallow Cookie Bars

Call them chocolate chip marshmallow cookie bars. Call them s’mores bars. Either way, I promise that the combination of graham crackers, melted chocolate, and gooey marshmallows in these bars will bring back your fond campfire memories. All without the smoke.


My s’mores bars aspirations started out first as an adaptation of my chocolate chip cookie recipe. I replaced a cup of flour in the recipe with ground graham crackers. I added marshmallows to the batter. And I put a few more marshmallows on top towards the end of baking.

Result? I hadn’t accounted for the extra sugar in the graham crackers. Way too much spread from the marshmallows in the batter. And I added the extra marshmallows too early in the baking. Lessons learned.

s'mores cookies on a baking sheet

So when I was talking with my friend Angela at Flash in the Pans about making one of her recipes for this week’s reddit 52 week baking challenge (Week 36: Friendship Challenge), and she suggested her Air Fryer S’Mores Brownies, I got all excited.

a pan of s'mores brownies

Because I don’t own an air fryer, I baked the brownies in the oven, using the same temperature and time. Angela recommended browning the marshmallows under the broiler for about one minute.

S’mores perfection! I think they might even have been better on the second day.

Some notes about my recipe

The development of this recipe for chocolate chip marshmallow cookie bars combined these two past attempts. One advantage of the cookie bar from is that it eliminates the problem of spread.

I limited the marshmallows to the s’mores inspired top but again added pulverized graham crackers into the chocolate chip cookie bar. I decreased the amount of sugar this time but browned the butter to give the bar more oomph.

If you’ve never browned butter before, the secret is to cook it slowly over medium-low heat, and listen for the popping to stop.

browned butter in a pan

You don’t need a stand mixer for this recipe, but I think it helps when beating in the eggs and vanilla.

You also probably could get by without a food processor to pulverize the graham crackers (shown in Panel #1 below) as long as you can crush them finely without it.

I sifted the flour and other dry ingredients into the graham crackers (shown below in Panel #2), because I always seem to have a clump or two, but you could always just whisk it well.

Finally, panels #3 and #4 show the batter after beating in the eggs and vanilla (in panel #3) and then after stirring in the dry ingredients by hand (in panel #4).

Four panels showing the pulverized graham crackers, the dry ingredients, the sugar and butter and egg mixture, and then the final batter

Is it possible to add too many chocolate chips?

When the batter has cooked, it should be slightly browned and pulling away slightly at the edges (Panel #1 below). A toothpick inserted should come out clean, and it should feel slightly firm to the touch. Sprinkle on the broken graham crackers (Panel #2) and then the mini marshmallows (Panel #3).

Set an oven rack so the pan will sit about 6-8 inches from the broiler, and keep a close eye on the doneness of your marshmallows. Panel #4 shows the marshmallows broiled for 45 seconds.

FAQs about these chocolate chip marshmallow cookie bars

What is the history of s’mores?

I read in this history of s’mores in Food and Wine that graham crackers were developed to curb sex drive and just had to share that tidbit with you.

Do I really have to weigh my ingredients?

No, you don’t have to do anything, but you will get better/more consistent results if you weigh your ingredients, especially for baking. I’m offering to buy a basic kitchen scale for the first 10 U.S. readers to sign up for my newsletter (see below) and comment that you would like to use a kitchen scale.

Can I use light brown sugar instead of dark brown sugar?

Yes. Dark brown sugar just has a little bit more molasses in it, which gives it a slightly richer flavor, but light brown will work perfectly. You can read more about the difference in sugars here in this great read from Serious Eats.

How do I separate an egg?

Separating eggs is pretty easy, especially when it’s not critical to do it perfectly, like it is for making meringues. To separate the egg, tap the egg against the edge of a small bowl. Use your thumbs to split the shell apart, trying to keep the yolk in one half of the shell. Pass the yolk back and forth between the halves of the shell until most of the white has dropped into the bowl. Egg whites are great for making granola.

Could I substitute chopped chocolate for the the chocolate chips?

Sure. The topping should take about 4 ounces of whatever chocolate you prefer.

Can I use a kitchen torch to brown the marshmallows instead of the broiler?

Yes. That should work. In fact, I bought a torch to make this recipe but decided to use the broiler again instead.

Can I line my pan with parchment paper like I normally do for brownies?

I greased the pan instead of lining it because I was afraid of what the broiler might do to the parchment. Feel free to use parchment if you are using a kitchen torch instead of the broiler.

Can I freeze these chocolate chip marshmallow cookie bars?

The marshmallow topping wouldn’t freeze well, but you could freeze the pan of baked batter after it cools. Just double wrap it tightly and let it come to room temperature before proceeding with the recipe.

a pan full of chocolate chip marshmallow cookie bars

Chocolate Chip Marshmallow Cookie Bars

Prep Time 25 minutes
Cook Time 35 minutes
Total Time 1 hour
Servings 16 bars
Author uglyducklingbakery


  • Stand or hand mixer, optional
  • Food processor, optional


  • cup (5.3 ounces/151 grams) unsalted butter plus more for greasing the pan
  • 6 whole graham crackers (or 3.2 ounces/90 grams graham cracker crumbs)
  • cup (3.0 ounces/83 grams) bleached all-purpose flour
  • ½ teaspoon salt
  • ½ teaspoon baking powder
  • ¼ teaspoon baking soda
  • ½ cup (3.4 ounces/96 grams) dark brown sugar
  • 1 large egg
  • 1 egg yolk
  • ½ teaspoon vanilla extract
  • 8 ounces semisweet or bittersweet chocolate chips


  • 2 whole graham crackers, broken into pieces
  • ½ cup mini marshmallows
  • 4 ounces semisweet or bittersweet chocolate chips


  • Preheat the oven to 325°F. Grease an 8"x8" or 9"x9" square baking pan.
  • Brown the butter by heating it on medium-low in a small pot. The butter will melt and bubble. Turn off the heat when the bubbling stops. The butter should have darkened and smell slightly nutty. Remove from heat and let cool slightly.
    2/3 cup (5.3 ounces/151 grams) unsalted butter
  • Pulverize the graham crackers in a food processor or by hand and add it to a medium bowl.
    6 whole graham crackers (or 3.2 ounces/90 grams graham cracker crumbs)
  • Sift the flour, salt, baking powder, and baking soda into the bowl with the graham crackers and whisk to mix.
    2/3 cup (3.0 ounces/83 grams) bleached all-purpose flour, 1/2 teaspoon salt, 1/2 teaspoon baking powder, 1/4 teaspoon baking soda
  • In the bowl of a stand mixer (or another medium bowl if using a hand mixer or mixing by hand), combine the sugar and brown butter.
    1/2 cup (3.4 ounces/96 grams) dark brown sugar
  • Add in the egg and egg yolk and beat on medium speed for one minute.
    1 large egg, 1 egg yolk
  • Add the vanilla and beat on medium speed for one minute.
    1/2 teaspoon vanilla extract
  • Stir in the dry ingredients by hand and then add the chocolate chips and mix.
    8 ounces semisweet or bittersweet chocolate chips
  • Spread the mixture evenly in the prepared pan and bake for 30-35 minutes, until the bars start to brown and pull away from the sides of the pan, a toothpick inserted in the middle comes out clean, and the cookie feels somewhat firm.
  • Take the pan out of the oven and set the oven to broil with a rack 6-8 inches from the broiler.
  • While the broiler is heating, add the graham cracker pieces and then the mini marshmallows to the pan.
    2 whole graham crackers, broken into pieces, 1/2 cup mini marshmallows
  • Broil for 45-60 seconds, watching closely, until the marshmallows have achieved your ideal brownness.
  • Remove from the oven, sprinkle on the chocolate chips, and cover with foil for 5-10 minutes.
  • These chocolate chip marshmallow cookie bars can be stored at room temperature for up to one week.


– feel free to substitute any type of chocolate – chopped or chip – that you like

What’s next?

If you make these chocolate chip marshmallow cookie bars, please leave a comment here or share a pic with me on Instagram!

Check out some other uglyducklingbakery cookie and brownie recipes like these peanut butter Rice Krispie treats, lemon lavender shortbread, or ube macaroons.

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Previous challenges:
Week 1: New Year new recipe – blueberry galette
Week 2: seasonal – Smitten Kitchen’s grapefruit pound cake
Week 3: Great British Bake Off – Kate’s sticky toffee apple caramel cake
Week 4: Australia – sausage rolls
Week 5: bite sized – cookies
Week 6: Chinese New Year – mushroom bao
Week 7: new tool – baguette baker
Week 8: chocolate – chocolate peanut butter bonbons
Week 9: timed bake – under 1 hour! chocolate chip scones
Week 10: allergy/diet restriction – macarons
Week 11: quick breads – kale and cheese quick bread
Week 12: signature bake – purple cow bread
Week 13: enriched breads (kale and cheese babka fail)
Week 14: childhood favorite –fudgy triple layer chocolate cake with chocolate ganache frosting
Week 15: decorating challenge – purple velvet cake
Week 16: crispy crunchy – bacon cheddar popcorn
Week 17: p52 of a favorite cookbook, or your favorite blog – chocolate peanut butter drip cake
Week 18: pâte à choux – bacon cheese puffs
Week 19: veggies turned sweet – red velvet beet waffles
Week 20: plating – chocolate chip cookie (butter challenge)
Week 21: Birthday Party! – chocolate orange cake
Weed 22: Scandinavian – Swedish apple cake (plus a bonus sourdough discard apple cake)
Week 23: Layers – Pecan apple oat bars (post is pending)
Week 24: Tarts – rainbow fruit tart
Week 25: Bagels and donuts – maple donut cake
Week 26: Surprise inside – surprise heart yeast bread (pending)
Week 27: Local favorite – Rainier cherry crisp
Week 28: Seasonal ingredients – blackberry lemon bread
Week 29: French dessert – peanut butter banana clafoutis (a classic with non-classic flavors!)
Week 30: Savory baking – pizza
Week 31: Unusual ingredient – juniper lime drizzle cake
Week 32: Gelatin (homemade marshmallows) and 33: Picnic – peanut butter rice krispie treats
Week 34: Brunch – spinach and feta muffins
Week 35: Laminated dough – puff pastry cinnamon twists

Next week: Sweet and salty

the mess in the sink after making chcooalte chip marshmallow cookie bars

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