Cookies / Desserts / Vegetarian

Fluffernutter Cookie Bars

These gooey, marshmallowy Fluffernutter Cookie Bars are perfect year-round. They are a crowd-pleasing decadent treat that’s truly hard to beat!

Stack of Peanut Buttery Marshmallowy Fluffernutter Bars

Now, when I am craving a rich, decadent dessert that isn’t all about chocolate… I look no further than these Fluffernutter Cookie Bars! I mean, who can resist the peanut buttery, marshmallowy goodness of these Fluffernutter Cookie Bars?! Just take a look at that marshmallow fluff! Rick is my taste-tester and kept sneaking into the kitchen to get more. They disappeared REAL quick!

Ingredients for Fluffernutter Cookie Bars

  • Creamy-style Peanut Butter
  • Unsalted Butter
  • Brown Sugar
  • Granulated Sugar
  • Eggs
  • Vanilla Bean Paste (or Vanilla Extract)
  • Baking Soda
  • Salt
  • All-purpose Flour
  • Caramel Pieces
  • Dark Chocolate Chips
  • Marshmallow Fluff
Fluffernutter Cookie Bars shown on a cooling rack

How to make Fluffernutter Cookie Bars

  • Preheat oven to 350*F. I recommend that once your oven alerts you the preheat phase is complete – allow an additional 15 or so minutes to let your oven come to a consistent temperature for a more even bake.
  • Prepare a baking dish – I suggest a 9×13 baking dish, however, you can use a 9×9 or 11×7. – depending what you have on hand. Prepare dish by lining it with parchment paper, this will allow easy removal once the bars have set.
  • In a large bowl – add all dry ingredients and whisk until well combined.
  • Using a stand mixer with paddle attachment- add peanut butter and unsalted butter and mix until combined. Next, add sugars and mix. Then, add eggs – one at a time and mix. Add vanilla and combine. Add flour mixture 1/2 cup at a time and mix well between each addition.
  • Once all of the flour mixture has been added – Mix in the caramel pieces and chocolate chips.
  • Press half the dough on the bottom of the prepared baking dish and bake for 5 minutes and take out of oven.
  • Next, spread Marshmallow Fluff on top of the dough – I find it best to use the back of a warm metal spoon (run it under hot water to help warm it up). It won’t look perfect and that is A-OK.
  • Gently press the remaining dough flat and lay it on top of the marshmallow fluff. You will see spaces – this is expected. Try to get the dough as even as possible.
  • Bake for 22-25 minutes or until the top is a lovely golden brown
  • Once out of the oven allow the Fluffernutter Cookie Bars to cool for at least an hour so they will fully set.
Stack of Fluffernutter Cookie Bars with two jars of milk in the background

Can I swap or add any fillings?

Of course! Full disclosure: I have not tested these Fluffernutter Cookie Bars with anything other than the caramel pieces and dark chocolate chips listed below. However, there are multiple options that would be delicious in this recipe. Here are some of my favorite recommendations:

  • Shredded Coconut
  • Semi-Sweet Chocolate Chips
  • Dried Cherries
  • Toffee Bits
  • Chopped Reese’s Peanut Butter Cups
  • Oats

I’m telling you, these Fluffernutter Cookie Bars will be the hit of your household or any party you take them too! Our family loves them and asks us to bring them to family gatherings! They’ll totally be worth it!

Love Peanut Butter and Chocolate? Check out these easy No Bake Peanut Butter Bars!

Stack of Peanut Buttery Marshmallowy Fluffernutter Bars

Fluffernutter Bars

Yield: 15 bars
Prep Time: 10 minutes
Cook Time: 30 minutes
Total Time: 40 minutes

These gooey, marshmallowy Fluffernutter Bars are perfect year-round. They are a crowd-pleasing decadent treat that's truly hard to beat.


  • • 1/2 cup peanut butter, room temperature
  • • 1/2 cup butter, room temperature
  • • 1 ¼ cup light brown sugar
  • • ½ cup granulated sugar
  • • 2 eggs
  • • 3 tsp vanilla bean paste (or vanilla extract)
  • • 1 tsp baking soda
  • • 1 tsp salt
  • • 2 1/2 cups all-purpose flour
  • • 1 cup Kraft Caramel Pieces
  • • 1 cup dark chocolate chips
  • • 8 oz marshmallow fluff


  1. Preheat oven to 350*F
  2. Prepare 9x13 baking dish and line with parchment paper
  3. In a large bowl add flour, baking soda and salt, whisk and set aside
  4. Cream peanut butter and butter in a stand mixer with a paddle attachment
  5. Add brown and granulated sugars to mixer and beat until light and fluffy
  6. Add eggs, one at a time mixing well between each addition
  7. Add vanilla
  8. Next, add flour mixture 1/2 cup at a time, mixing well between each addition
  9. Then, add caramel pieces and chocolate chips to dough
  10. Spread 1/2 of dough mixture on the bottom of a prepared baking dish
  11. Bake for 5 minutes
  12. Take out of oven and spread marshmallow fluff on top of pre-baked dough
  13. Then, press the remaining dough on the top of the marshmallow fluff
  14. Bake for 22-25 minutes until the top of the bars are a lovely golden brown
  15. Remove from oven and let sit for at least an hour to allow the bars to fully set.


These Fluffernutter Bars can be stored in an airtight container for up to 5 days.

Nutrition Information:
Yield: 15 Serving Size: 1
Amount Per Serving: Calories: 432Total Fat: 15gSaturated Fat: 7gTrans Fat: 0gUnsaturated Fat: 6gCholesterol: 42mgSodium: 432mgCarbohydrates: 71gFiber: 2gSugar: 49gProtein: 6g

Estimated nutritional value may vary based on brands used to create recipe.

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  • Beth
    June 12, 2020 at 12:29 pm

    These look so yummy! I can’t wait to make these for my family. Thanks!

    • Kerri
      June 16, 2020 at 9:16 am

      You’re welcome! They’re really delicious!

  • Dorothy at Shockingly Delicious
    June 12, 2020 at 7:28 pm

    Oh. My. GAWD. Give me all that marshmallow, and step away from the plate. It’s mine!

    • Kerri
      June 16, 2020 at 9:16 am

      I’ll gladly share!

  • Erin | Dinners,Dishes and Dessert
    June 12, 2020 at 10:22 pm

    These Fluffernutter Cookie Bars would disappear in our house!

    • Kerri
      June 16, 2020 at 9:15 am

      They did not last long in ours!

  • katerina @
    June 14, 2020 at 2:54 pm

    These cookie bars are incredible! I bet they taste ahhmaazing!

    • Kerri
      June 16, 2020 at 9:15 am

      Perfect when you need a little extra something!

  • Catalina
    June 15, 2020 at 4:04 am

    I would like one of these delicious cookie bar for my afternoon snack!

    • Kerri
      June 16, 2020 at 9:15 am

      Do it! 😉

  • Kevin
    June 15, 2020 at 3:12 pm

    What a great sweet treat to enjoy!

    • Kerri
      June 16, 2020 at 9:14 am

      They’re SO good!


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