Super indulgent, soft and chewy s’mores cookie bars that combine all the classic flavors of campfire s’mores: cinnamon-spiced, graham infused cookie dough studded with gooey chocolate and melted mini marshmallows. Everyone in the family will love these!

Chewy s'mores cookie bars with chocolate chips and mini marshmallows, sliced into squares on white parchment paper.

We’re heading down a quite indulgent path today with these soft and chewy s’mores cookie bars. 

They begin simple enough, as rich and buttery, traditional chocolate chip cookie bars, but are elevated with tons of classic s’mores flavor. From the sweet and salty graham cracker crumbs in the cookie dough, to the ribbons of melted chocolate throughout, to the gooey mini marshmallows and dark chocolate chips on top, these cookie bars are delicious, and decadent, and bound to become one of your favorite Summer treats!

Side note: if you can’t get enough of this flavor combination, you have got to try this chocolate s’mores tart, too. A brown sugar, graham cracker crust. Creamy dark chocolate ganache filling. All topped with swirls of toasted, homemade marshmallow meringue. It’s equally incredible.

Happy baking!!

An unwrapped bar of bittersweet Theo chocolate.
A close up of semisweet chocolate chips.
Chewy s'mores cookie bars with chocolate chips and mini marshmallows, sliced into squares on white parchment paper.

S’more Bar Ingredients:

We’re working with mostly standard baking pantry staples – plus some s’mores essentials – to make these chocolate-y cookie bars. Here’s what you’ll need:

  • graham crackers: the cookie dough includes crushed graham crackers to really capture the classic flavor of s’mores.
  • flour: regular, all-purpose flour forms the base of the dry ingredients. A gluten-free all-purpose flour blend should work well, too.
  • baking powder: for just the right amount of lift.
  • sugar: you’ll need both granulated and brown sugar for sweetness, a wonderfully chewy texture, and a shiny top.
  • butter: melted butter adds rich flavor and a chewy texture.
  • eggs: you’ll need one egg plus an extra yolk.
  • vanilla, cinnamon, and salt: a delicious trifecta for lots of flavor.
  • chocolate: of course! Two kinds of melted chocolate are a must here – chopped bittersweet chocolate creates ribbons of deliciousness . If you want to pay even greater homage to classic s’mores, you could even add a few mini Hershey bars on top.
  • marshmallows: and it wouldn’t be a s’more without some gooey, melted marshmallow. We’re using mini ones here, swirled into the batter and scattered on top.

Find all the exact ingredients and detailed instructions in the recipe card, below.

Chewy s'mores cookie bars with chocolate chips and mini marshmallows, sliced into squares on white parchment paper.

S’mores Bars FAQs

Can you use marshmallow fluff?

Sure. Store-bought marshmallow creme can be dolloped on top or swirled into the batter. I do find it a bit harder to work with than regular marshmallows, but a small cookie scoop makes it a bit more manageable. You can also use standard size marshmallows, though I’d recommend cutting them into smaller pieces (kitchen shears work well for this).

How to store:

Once cooled, keep leftover s’more bars in an airtight container at room temperature for 2-3 days.

Chewy s'mores cookie bars with chocolate chips and mini marshmallows, sliced into squares on white parchment paper.

More Chocolate-y Desserts to Make Next:

If you make these chewy S’mores cookie bars, be sure to leave a comment and rating below letting me know how you liked them! ★★★★★ Star ratings are especially helpful because they help others find my recipes too. xo, Laura

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Chewy s'mores cookie bars with chocolate chips and mini marshmallows, sliced into squares on white parchment paper.

S’mores Cookie Bars

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  • Author: Laura Bolton – Fork Knife Swoon
  • Prep Time: 25
  • Cook Time: 20
  • Total Time: 45 minutes
  • Yield: 12 Cookie Bars
  • Category: Baking, Desserts
  • Method: Baking
  • Cuisine: American
  • Diet: Vegetarian
Print Recipe

Description

Super indulgent, soft and chewy s’mores cookie bars that combine all the classic flavors of campfire s’mores: cinnamon-spiced, graham infused cookie dough studded with gooey chocolate and melted mini marshmallows. Everyone in the family will love these!

Ingredients

  • 3 graham cracker sheets
  • 1–1/4 cup (150g) all-purpose flour
  • 1/2 tsp baking powder
  • 1/2 tsp Kosher salt (such as Diamond Crystal)
  • 1/4 tsp ground cinnamon
  • 1/2 cup (113g or 1 stick) unsalted butter, melted
  • 3/4 cup (150g) light brown sugar, packed
  • 1/4 cup (50g) granulated sugar
  • 1 tsp pure vanilla extract
  • 1 large egg
  • 1 large egg yolk
  • 2 oz bittersweet chocolate (60-70% cacao), roughly-chopped
  • 1/2 cup mini marshmallows, divided
  • 1/4 cup (42g) semisweet chocolate chips

Instructions

  1. Preheat the oven to 350℉. Line a 8×8-inch square baking pan with parchment paper. Set aside.
  2. Crush the graham crackers into a sandy, fine powder. You can either use a food processor for this, or place the grams in a Ziploc bag and use a rolling pin to crush them. You should end up with about 5.5 Tablespoons of graham cracker crumbs.
  3. Add the graham crumbs to a medium mixing bowl. Whisk together well with the flour, baking powder, salt, and cinnamon, until well-combined. Set aside.
  4. In a stand-up mixer fitted with the paddle attachment, mix together the melted butter and sugars on medium speed until smooth and creamy. Scrape down the sides of the bowl as needed, then mix in the vanilla.
  5. Add the egg and yolk, and mix until completely combined and the mixture has slightly lightened in color, about 30 seconds.
  6. Turn the mixer down to low speed, and spoon in the flour mixture. Mix until just combined, scraping down the sides of the bowl with a spatula, as needed. Stir in the chopped chocolate and half of the marshmallows.
  7. Turn the cookie dough out into the prepared baking dish, and use an offset spatula to even out the top and smooth the dough into an even layer. The dough will be thick.
  8. Sprinkle the chocolate chips on top.
  9. Bake for 18-22 minutes, until the bars are golden, a bit shiny, and look mostly set. A cake-tester inserted into the center should come out mostly clean (if you hit some chocolate that’s okay, but you don’t want there to be any cookie batter).
  10. Immediately top with the remaining marshmallows, which will begin to slightly melt into the top from the warmth of the cookie bars.
  11. Let the cookie bars cool in the pan for 15-20mins before slicing. Serve warm. Enjoy!!

Equipment

Notes

  • Make them gluten free: Substitute equal parts of a gluten-free all-purpose flour blend such as Bob’s Red Mill or King Arthur Flour. You’ll also need to use gluten-free graham crackers.
  • If you like salted sweets, try adding a very light sprinkle of flake sea salt such as Maldon, straight out of the oven.