Gooey, marshmallow-filled, chocolate-layered, graham-cracker oatmeal crumb coated S’mores Cookie Bars.
Can’t get enough of graham crackers, marshmallows, and chocolate? Us either! 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.
- White all-purpose flour
- Baking soda
- Salt: It balances and intensifies flavors
- Milk chocolate chips: We use milk chocolate because nothing screams S’mores like milk chocolate to me! That said, these bars are very sweet; if you’re concerned about sweetness use semi sweet or dark chocolate instead.
- Marshmallow fluff: Jet-Puffed Marshmallow Creme® (not sponsored; affiliate link) is by far my favorite fluff to use in these bars. If you don’t have access to marshmallow fluff, you can try making your own.
- Graham crackers: No S’mores treat is complete without these iconic crackers! We crush up just 2 crackers to mix into the topping for S’mores Cookie Bars.
How to make S’mores Cookie Bars
- Add melted and cooled butter to brown sugar.
- Mix to combine.
- Add in the flour, oats, baking soda, and salt
- Stir to form a thick cookie dough.
- Spread a little over half of the dough to the pan, press into an even layer, and bake.
- Sprinkle chocolate chips on top of the warm dough.
- Soften marshmallow fluff in the microwave.
- Spread on top of the chocolate chips.
- Crush 2 graham crackers and add to the remaining cookie dough.
- Stir to combine.
- Sprinkle over the marshmallow fluff and bake again.
- Let cool and set up, cut into bars, and enjoy.
Recipe tips
- Wait for the butter to cool to room temperature. If you add sugar to hot or even warm butter, it will melt the sugar and cause these S’mores Cookie Bars to be greasy.
- 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
- Parchment paper
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 8x8 or 9x9-inch baking pan with parchment paper and set aside. I prefer 8x8 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.
Can I double the recipe for a 9×13 pan?
I don’t see why not, but I haven’t ever tried it myself.
Been making these for nearly 3 years, always a 10 from everyone. I call it Death by Bob, hope that’s ok, Chelsea the real mvp. Really is the best.
Haha!! This comment made my day! I’m so happy to hear it’s a hit and I love your name for it 🙂 Thanks Bob!
These look delicious! I wanted to make them ahead to bring camping this weekend. Do they keep for a couple of days? Would I have to keep them refrigerated or is room temperature okay?
They actually aren’t the best after a couple of days or so just because of the marshmallow layer (gets hard and blah tasting). If you do make them ahead wrap them SUPER tightly and room temperature is fine as long as it’s not too hot they will be great 🙂 ENJOY!
can this recipe be doubled for a 9×13 pan?
I haven’t personally tried that, but I don’t see why that wouldn’t work 🙂
I made these tonight and while tasty, the top never formed a “dough” and didn’t bake into the other layers. I followed the recipe exactly. Any thoughts?
The top doesn’t really bake into the layers – it’s definitely it’s own layer that tends to mesh with the marshmallows as they get melted. I’ve never had any problems with it not baking all the way in all the times I’ve made these, so I’m not quite sure what’s going on. Did the bottom layer bake for you or was that not all the way baked either? Because that may suggest a cooler oven? Perhaps a few more minutes in the oven could bake it a little more. However, you’ll want to be careful that you don’t overcook it because the marshmallows will not be great.
Chelsea!!! oh my gawd, these look so good!!! After last night, you’d think I’d be all “sweets” out . . but I’m not!! Pinned!!
Hi! I’m just wondering what will happen if I sub in peanut butter instead of regular butter, then cut out sugar completely. I’ve made s’mores bars without sugar, but I used butter at that time. If I use peanut butter and a little milk, will the cookie part taste like peanut butter?
I’m sorry to not be of more help, but as I haven’t tried any of those swaps in this particular recipe I really couldn’t say if they would work out like you are thinking. I do think they would taste like peanut butter if you used that in place of the butter though.
I agree with Chelsea – my favorite S’mores dessert ever! I followed instructions exactly, and they turned out perfect. I refrigerated them after they cooled to make them easier to cut into bars. This one is a keeper. Just fantastic.
Yay! So great to hear they are your favorite S’mores dessert!! Still my favorite too 🙂 Thanks for the tip about putting them in the fridge for easier slicing! And thanks for the kind comment!
Yummmmmmm……I need to stop going onto foodgawker in the morning! Although this has oats in it, it is not breakfast! This is like carmelitas (http://onlyfitinjustenough.blogspot.ca/2014/01/carmelitas.html) meets s’mores….it looks so good, and this has taken first place and bumped a few things down on my list of things to make! I have a love of
s’more-ified foods, so you may be a blogging kindred spirit (if that’s o.k.!)! 🙂
Making these tomorrow morning, to take & share with friends at dinner. And a great way to use up the leftover s’mores ingredients from camping this summer! Thanks for the recipe!