These soft, chewy Peanut Butter S’mores Cookie Bars combine the classic s’mores combination of marshmallows, graham crackers, and chocolate with the irresistible addition of peanut butter! This recipe only dirties one bowl and is sure to become a favorite!

Cookie bars are a favorite around here for how easy they are to make, how little time they take to prep, and how versatile they are! 

There are so many fun flavor combinations to try, like s’mores!

Based off of our Peanut Butter M&M Cookie Bars, these Peanut Butter S’mores Cookie Bars have the same soft, chewy base that requires a limited amount of prep work and only one bowl!

Stuffed with peanut butter, graham crackers, marshmallows and chocolate chips, these bars would be good left at that.

However, we topped them with more marshmallows and graham crackers towards the end of the bake time to get toasty marshmallows and crunchy graham crackers in each bite!

To tie everything together, we topped the bars with broken milk chocolate candy bar pieces after pulling the cookie bars out of the oven. 

This allowed the chocolate to get melty and stick to the bars without the chocolate getting to melty and spreading too thin.

So, if you’re looking for a new summer favorite dessert, these bars are it!

How to Make One Bowl Peanut Butter S’mores Bars

Start by preheating your oven to 350 degrees Fahrenheit. 

Spray with non-stick cooking spray or line with parchment paper an 8×8 inch baking dish. You don’t want to skip this step. The melty marshmallows will cause the bars to stick.

In the bowl of a stand mixer, or with an electric hand mixer, cream together your butter, brown sugar, and sugar. Don’t be afraid to let your mixer run for a bit so that the mixture gets lighter in color and has a somewhat fluffy texture.

Add in the peanut butter, egg, and vanilla extract. Beat the mixture until smooth and creamy.

Next, you’ll add in the all-purpose flour, baking soda, and salt. Beat the dough until well-combined.

Stir in 1/2 Cup of the mini marshmallows, 1/2 Cup of coarsely crushed graham crackers, and all of the chocolate chips. (Feel free to use whatever chocolate chips you like best. We like to use dark chocolate chips to keep the bars from being too sweet.)

Evenly spread the dough into your prepared baking dish.

Bake for 10 minutes. Carefully remove from the oven, and top the bars with the remaining 1/2 Cup mini marshmallows and 1/4 Cup coarsely crushed graham crackers.

Return the baking dish back to the oven, and bake for an additional 6-9 minutes or until edges turn golden brown and center no longer appears “wet.”

Try not to overbake the bars if you want them to have a chewy texture. The center will set as it cools.

Remove bars from the oven to a cooling rack. Top with broken milk chocolate bar pieces.

Allow the bars to cool and the chocolate to harden before cutting into pieces and enjoying.

Store any leftovers in an airtight container.

Tips for Making S’mores Peanut Butter Bars

• Feel free to use whatever chocolate chips are your favorite. We like using dark chocolate chips to keep the bars from getting too sweet.
• You can use a 9×9 inch baking dish. The second baking time will be closer to 3-5 minutes instead of 6-9 minutes.
• If you like to have a bit of crunch in your bars and love the peanutty flavor, you can use crunchy peanut butter instead of creamy.

Love peanut butter and s’mores? More peanut butter s’mores recipes to try!

• Peanut Butter S’mores Seven Layer Bars
• No Bake Peanut Butter S’mores Bars
• Peanut Butter S’mores Granola Bites