S’mores Cookie Bars are gooey, marshmallow-filled, chocolate-layered, and graham-cracker oatmeal crumb coated perfection.
Try these Golden Grahams® cereal S’mores bars or S’mores cookies next!
A Must-Make S’mores Treat!
There are few things I love more in the summer than S’mores. And since bonfires and homemade S’mores aren’t as readily available as I’d like, I’ve resorted to making as many treats as possible with plenty of chocolate, lots of marshmallows, and graham crackers.
And S’mores Cookie Bars are one of my favorite creations as of late. These bars begin with a soft, chewy, and sugary oatmeal cookie layer and are loaded with creamy milk chocolate and fluffy sweet marshmallows.
S’mores Cookie Bars Ingredients
- Butter: Use unsalted butter to perfectly control the amount of salt in the bars.
- Light brown sugar: Pack the sugar when measuring.
- Old fashioned oats: Avoid quick oats or steel cut oats; they won’t work in this recipe.
- Flour: Stick with all-purpose flour for the best texture.
- Baking soda: Don’t skip this ingredient—it’s key for the right texture.
- Salt: It balances and intensifies flavors
- Milk chocolate chips: Semi sweet or dark chocolate also work.
- Marshmallow fluff: Jet-Puffed Marshmallow Creme® is by far my fave.
- Graham crackers: Crush them to a coarse texture to avoid large chunks.
How To Make S’mores Cookie Bars Tips
- Prep: Use an 8×8 pan for thicker bars.
- Make dough: Ensure butter is cooled to avoid greasy bars.
- Press half of the dough into the pan: Press evenly for uniform baking.
- Bake: Keep an eye on the crust—don’t overbake it.
- Chocolate & marshmallows: Warm the fluff to make it easier to spread.
- Add graham crackers: Crush crackers coarsely to avoid large chunks.
- Add top layer of dough: Don’t worry about covering it completely—let the marshmallow peek through.
- Bake: Keep an eye on the top to prevent overbaking.
Recipe Tips
- Line the baking pan. These bars are sticky! Make sure to line the pan with parchment paper for easy removal.
- Spoon and level the flour: to avoid packing too much flour into the cookie base. Watch the linked video if you need some guidance.
- Use high-quality milk chocolate for best results. You’ll get both a better melt and better flavor. My favorite for S’mores Cookie Bars is Ghirardelli® or Guittard®. Cheaper brands can have a waxier content that is far less flavorful.
Storage
Leftovers?
- Cool and Cut: Allow bars to cool completely in the pan, then lift them out using the parchment paper and cut into squares.
- Store Airtight: Place bars in an airtight container with parchment paper between layers to prevent sticking.
- Keep Fresh: Store at room temperature for up to 3 days or refrigerate for up to 1 week.
More Delicious Desserts
- Funfetti Bars cookie base with marshmallows and candy topping
- 7 Layer Bars with a graham cracker crust
- Carmelitas caramel chocolate oatmeal bars
- Caramel Cookie Bars shortbread cookie bars with a caramel center
- Vanilla Cheesecake Bars with a berry topping
S’mores Cookie Bars
These S'mores Cookie Bars have everything you love about campfire s’mores, all packed into a gooey, layered treat! Melty marshmallows, rich chocolate, and a graham cracker oatmeal crumb crust that holds it all together.
Equipment
- 8 x 8-inch baking pan or 9 x 9-inch for thinner bars
Ingredients
- 3/4 cup unsalted butter partially melted and cooled
- 3/4 cup light brown sugar firmly packed
- 1 cup all-purpose flour
- 1 cup old fashioned oats do not use quick or steel oats
- 1 teaspoon baking soda
- 1/2 teaspoon salt
- 1 (12-ounce) bag milk chocolate chips
- 1 (7-ounce) jar marshmallow fluff I use Jet-Puffed Marshmallow Creme
- 2 graham crackers
Instructions
- Preheat oven to 350°F. Line an 8×8 or 9×9-inch baking pan with parchment paper and set aside. I prefer 8×8 pan for thicker bars, but either works.
- In a large bowl, mix the melted and cooled butter (see note 1), brown sugar, flour, oats, baking soda, and salt. Stir until combined in a thick cookie dough. Divide the mixture in half and press one half into the prepared pan.
- Bake at 350℉ for 8 minutes, then remove.
- Immediately out of the oven, sprinkle the chocolate chips evenly over the cookie crust. Warm the marshmallow fluff in the microwave (make sure there is no metal/foil topping on the fluff or don’t microwave) for 7 seconds. Spoon the marshmallow fluff on top of the chocolate chips and, working slowly and carefully, gently smooth into one layer.
- Crush the 2 graham crackers (I put them both in a bag, seal the bag, and crush with a wooden spoon or handle of a knife; just a coarse crush is enough). Add the crackers to the rest of the cookie dough mixture and stir to combine. Crumble the cookie dough mixture over the marshmallow fluff. Bake another 13–15 minutes until the top layer is lightly browned.
- Remove from oven and allow to cool at room temperature for at least 1 hour before cutting into the bars. Using the parchment paper overhang, pull bars out and cut with a sharp knife. Best enjoyed within 2–3 days (store in an airtight container).
Video
Recipe Notes
Note 1: Don’t add hot butter to the sugar—it will melt the sugar and cause greasy bars.
Storage: Store bars in an airtight container with parchment paper between layers to prevent sticking for up to 3 days, or refrigerate for up to 1 week.
Nutrition
Serving: 16bars | Calories: 205kcal | Carbohydrates: 32.9g | Protein: 1.9g | Fat: 9.1g | Cholesterol: 23mg | Sodium: 42mg | Fiber: 1g | Sugar: 17g
Nutrition information is automatically calculated, so should only be used as an approximation.
LOVE the new look! it is gorgeous, and the bars look equally as good!
Congrats on the new site design – love it!
LOVING all the s’mores recipes and the new & improved site!!! truly looks fabulous – All the best with it!!! xx
Oh my goodness, these look amazing.
I have really enjoyed all these s’mores week posts. Wish I could taste every single one of them! And I absolutely love your new blog design, Chelsea. 🙂 These bars look so good with that gooey marshmallow. Mmmm. 🙂 Pinned!
Girlfriend, I dub you Queen of creative desserts! Your creativity amazes me! I wish I had that knack for desserts! And LOVE the new site! It looks awesome!!
Love the new design and these S’mores gooey bars!! Such a fabulous combination, need to make these!
I love the site it looks INCREDIBLE!!! and the recipe looks AMAZING!!!
Chelsea, that moving picture is AWESOME!! and so are these bars, obviously. Ok, you totally sold me by saying that these are your absolute favorite s’mores dessert ever!! So creative to use oatmeal. I was always one to reach for any dessert with oatmeal in it!! Pinned for sure, thanks lovely!
Love the new site layout and these AMAZING s’mores bars!