Imagine s’mores in bar form, this is just that! Gooey peanut butter s’mores bars have a graham cracker chocolate chip cookie base and ribbons of marshmallow fluff throughout. A delicious twist on everyone’s favourite summer dessert!
Can you believe it’s already August? I feel like summer has seriously just been flying by!
Between the nationwide forest fires and the rainy days here in Toronto, we’ve had no campfires this summer. That’s where these bars come in handy!
The cookie dough comes together in one bowl and is super simple to make. It’s got brown butter, peanut butter, chocolate chips, and graham cracker crumbs. Yum!
If you haven’t added peanut butter into your s’mores now, you’re missing out!
Once the dough is created, it’s spread onto an 8×8 pan. Marshmallow fluff is layered on top. Then, chocolate chips and graham cracker pieces. Lastly, some more cookie dough to seal it all in!
My favourite part about this recipe is the ribbons of marshmallow fluff peeping through the top of the bars. So gooey and good!
Why this recipe works
Easy to make – Simple cookie dough layered with marshmallow and chocolate!
Gooey bars – Marshmallow fluff is layered in between before baking!
Peanut butter – If you’re a peanut butter fan in your s’mores, you’ll love this recipe.
Party idea – Make these for your next BBQ or dinner party!
Here are a few key ingredients you’ll need for this recipe! Full measurements in the recipe card below.
Butter – I always use unsalted! This will be melted and browned.
Chocolate chips – Semi-sweet are used, but feel free to use white, milk, or dark! You can also chop up a chocolate bar for extra gooey pockets of chocolate.
Eggs – One egg yolk and one egg at room temperature.
Flour – All-purpose flour is used.
Graham crackers – Graham cracker crumbs are added into the cookie dough, as well as pieces are layered in between the bars.
Marshmallow fluff – I used store-bought marshmallow fluff. Marshmallows cannot be a substitute for this recipe.
Peanut butter – This is used inside the cookie dough. Feel free to use creamy or chunky. Do not use natural as it is too runny.
Step by step instructions
Step 1 – Prep. Grease the pan. For easy removal of the brownies, place parchment paper on the bottom and 2 sides of the pan. Grease again and then set aside.
Step 2 – Brown butter. Check out recipe card for details on how to brown butter! Cool completely (20-30 minutes).
Step 3 – Whisk wet ingredients. In a large bowl, add browned butter, brown sugar, and peanut butter. Mix until well combined.
Once whisked, add in egg, egg yolk, and vanilla and whisk until light and fluffy.
Step 4 – Add in dry ingredients. Toss in graham cracker crumbs, flour, baking soda, baking powder, and salt. Using a spatula, gently fold until a soft cookie dough forms.
Step 5 – Add in chocolate chips. Toss in the chocolate chips and mix in a few times.
Step 6 – Transfer into prepared pan. Add 3/4’s of the dough into the bottom of the pan and spread evenly using your hands or a spatula. Make sure the entire bottom of the pan is covered!
Step 7 – Layer, layer, layer! Add marshmallow fluff on top and spread as best as you can. I used a spatula and a spoon together.
This will help you with clean slices and washing the pan afterwards. Sometimes it’s tricky to clean off marshmallow fluff.
Add chocolate chips and graham crackers. Then flatten out the remaining 1/4 of the cookie dough and distribute around the bars.
Step 8 – Bake! Bake the bars for 25-30 minutes or until the edges are a light golden brown.
Slice and enjoy! These bars are best enjoyed within 3 days of baking them!
Expert Baking Tips
Here are a few expert baking tips from my kitchen to yours!
- Use a gram scale for most accurate measurements. Especially for the dry ingredients!
- Make sure to line the pan with parchment paper! This is especially important for this recipe because it’s hard to clean off marshmallow fluff from your pan.
- Use creamy or chunky peanut butter, not natural.
- Line the bottom and two sides with parchment paper. Grease the other two sides. This will allow for the easiest removal from the pan.
Can I use marshmallows instead of marshmallow fluff?
After recipe testing, I would have to say no. Marshmallows didn’t spread enough, and mini marshmallows spread to much. Marshmallow fluff is the only one that spread the perfect amount for me.
Is marshmallow creme and marshmallow fluff the same thing?
Yes! It’s just got different names in different places around the world 🙂
Can I eat these warm?
Absolutely! They will *definitely* be gooey, but that’s what this recipe is all about! We’re making s’mores bars here! Haha
Can I double this recipe?
Yes! Double the recipe and bake in a 9×13 pan. Check the bars are 25 minutes of baking.
Storing & Freezing
Store the bars on your counter for up to 3 days.
Freeze the bars in an airtight container or ziplock bag for up to 1 month.
My favourite way to eat these bars is warm! They are so gooey and good and remind me of a campfire!
Check out these recipes
Peanut Butter S’mores Bars
- 1/2 cup butter melted and browned
- 3/4 cups dark brown sugar
- 1/3 cup creamy peanut butter
- 1 egg room temperature
- 1 egg yolk room temperature
- 1 tbsp vanilla
- 1 3/4 cups all-purpose flour
- 1/4 tsp baking powder
- 1/2 tsp baking soda
- 1/4 tsp salt
- 4 tbsp graham cracker crumbs
- 1/2 cup marshmallow fluff
- 1 cup chocolate chips divided
- 1/2 cup graham cracker pieces
- Preheat the oven to 350℉/180℃. Grease an 8×8 inch square pan. For easy removal of the bars, place parchment paper on the bottom and 2 sides of the pan. Grease again and then set side.
- Brown the butter: Melt the butter in a medium sized pan over medium heat. Once it melts, it will crackle, then become foamy – continue mixing the butter while this happens to prevent burning. The butter will go from melted to golden brown quickly, and you'll know it's almost done when the aroma of browned butter arrives. The whole process should take about 5 minutes! Once golden, remove from heat and transfer to a glass bowl. Let the butter cool for 30 minutes (Do not let it harden) while you prep on the rest of the recipe.1/2 cup butter
- In a large mixing bowl, add cooled browned butter, brown sugar, and peanut butter. Mix until combined.3/4 cups dark brown sugar, 1/3 cup creamy peanut butter
- Add in egg, egg yolk, and vanilla. Whisk until light and fluffy (2-3 minutes).1 egg, 1 egg yolk, 1 tbsp vanilla
- Toss in the flour, baking soda, baking powder, salt, and graham cracker crumbs. Using a spatula, gently fold until well combined and a soft dough forms.1 3/4 cups all-purpose flour, 1/4 tsp baking powder, 1/2 tsp baking soda, 1/4 tsp salt, 4 tbsp graham cracker crumbs
- Add in 3/4 cups of chocolate chips and mix in.1 cup chocolate chips
- Take 3/4's of the cookie dough and spread it along the bottom of your prepared pan. Make sure the entire bottom is covered well!
- Spread marshmallow fluff evenly on top. This can be tricky, so place smaller spoonfuls of it onto the dough and that will make it easier to spread around.1/2 cup marshmallow fluff
- Sprinkle chocolate chips and graham crackers on top. Using your hands, flatten the remaining 1/4 of the peanut butter dough and randomly place on top of the bars. Leave some holes in between for the ribbons of marshmallow fluff to peak through!1/2 cup graham cracker pieces
- Bake for 25-30 minutes. You'll know it's ready when the edges are a light golden brown colour. The marshmallow fluff may rise up, but it should flatten once removed from the oven and cooled off.
- Slice and enjoy!