Reese’s Pieces Peanut Butter Fluffernutter Cookies with Peanut Butter Buttercream


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What’s a fluffernutter? If you have to ask, you have major eating to do to make up for lost time.

Fluffer is marshmallows. Nutter is peanut butter. Two of my favorite ingredients in one cookie.

Reese's Pieces Peanut Butter Fluffernutter Cookies with Peanut Butter Buttercream - Recipe at

And they’re some of the best cookies I’ve ever made.

For the cookies, I used my recipe for Reese’s Pieces Soft Peanut Butter Cookies. It’s been very popular with readers and the cookies are supremely soft, squishy, tender, and moist, with just a tiny amount of chewiness.

Reese's Pieces Peanut Butter Fluffernutter Cookies with Peanut Butter Buttercream - Recipe at

Reese’s Pieces and chocolate chips are abundantly studded throughout the very peanut buttery dough.

No need to wonder if these are peanut butter cookies after tasting the peanut butter intensity. Some peanut butter cookies recipes are so blah and lackluster, but not these.

The chocolate chips melt, and get gooey, while the Reese’s Pieces add crunchy texture. I love biting into their candy-coated shells amidst the soft, buttery dough.

Reese's Pieces Peanut Butter Fluffernutter Cookies with Peanut Butter Buttercream - Recipe at

After the cookies have baked for about 6 minutes, pull them out of the oven, top with half of a large marshmallow, and bake for another couple minutes. Just long enough to soften the marshmallows so they start to melt and a bit. Don’t let them turn into puddles of goo or develop color.

I love marshmallows and have never met a Rice Krispie Treat, Marshmallow Cookie Bar, or Smores Cookie that I didn’t love. They make an already really good cookie even better.

Reese's Pieces Peanut Butter Fluffernutter Cookies with Peanut Butter Buttercream - Recipe at

After the cookies cool a bit, top them with peanut butter buttercream frosting. It’s the literal icing on the cake.

Or on the cookie.

It’s creamy, fluffy, peanut buttery, and buttery, with just the right balance of salty-and-sweet. I want to put it on everything. Even broccoli.

Reese's Pieces Peanut Butter Fluffernutter Cookies with Peanut Butter Buttercream - Recipe at

The cookies are a peanut butter lover’s dream: Peanut butter in the dough, in the Reese’s Pieces, and in the buttercream.

And when mixed with chocolate chips and marshmallows, the range of flavors makes them irresistible.

Reese's Pieces Peanut Butter Fluffernutter Cookies with Peanut Butter Buttercream - Recipe at

The texture is something from my dreams. The cookie dough is supremely soft, the Reese’s Pieces add crunch, the chocolate chips are melty and soft, and the marshmallows are like biting into clouds.

Clouds that are topped with frosting from the heavens. It’s light, soft, fluffy, and lends even more squishiness.

As I was stacking the cookies and the frosting and marshmallows were squishing down, all I could think was, Don’t Squeeze the Charmin.

Reese's Pieces Peanut Butter Fluffernutter Cookies with Peanut Butter Buttercream - Recipe at

I finished them off with a pinch of chocolate sprinkles.

As if they needed anything else going on, but why not.

Reese's Pieces Peanut Butter Fluffernutter Cookies with Peanut Butter Buttercream - Recipe at

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5 from 2 votes

Reese's Pieces Peanut Butter Fluffernutter Cookies with Peanut Butter Buttercream

By Averie Sunshine
The cookies are a peanut butter lover’s dream: Peanut butter in the dough, in the Reese’s Pieces, and in the buttercream. The cookie dough is supremely soft, the Reese’s Pieces add crunch, the chocolate chips are melty and soft, and the marshmallows are like biting into clouds. Clouds that are topped with frosting from the heavens. It’s light, soft, fluffy, and lends even more squishiness to already supremely soft, moist, tender, gooey cookies. They’re some of the best cookies I’ve ever made.
Prep Time: 20 minutes
Cook Time: 9 minutes
Total Time: 29 minutes
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  • 1 large egg
  • 1 cup light brown sugar, packed
  • ¾ cup creamy peanut butter, do not use homemade or natural peanut butter; use Jif, Skippy, or similar
  • ½ cup unsalted butter, softened
  • 1 tablespoon vanilla extract
  • 1 ¾ cups all-purpose flour
  • ¾ teaspoon baking soda
  • pinch salt, optional and to taste
  • 1 cup Reese’s Pieces
  • 1 cup semi-sweet chocolate chips
  • about 12 to 15 large marshmallows, each sliced in half

Peanut Butter Buttercream Frosting

  • 4 tablespoons unsalted butter, softened (half of one stick)
  • about 1/3 cup creamy peanut butter
  • ¾ teaspoon vanilla extract
  • about 1 cup confectioners’ sugar
  • pinch salt, optional and to taste
  • splash of cream or milk, only if necessary to achieve desired consistency
  • chocolate sprinkles, optional for garnishing


  • For the Cookies – To the bowl of a stand mixer fitted with the paddle attachment (or large bowl and electric hand mixer), cream together the first 5 ingredients (through vanilla) on medium-high speed until light and fluffy, about 5 minutes.
  • Stop, scrape down the sides of the bowl, and add the flour, baking soda, optional salt, and mix on low speed until just incorporated, about 1 minute; don’t overmix.
  • Add the Reese’s Pieces, chocolate chips, and mix until just incorporated.
  • Using a medium 2-inch cookie scoop, form heaping two-tablespoon mounds (I made 27). Place mounds on a large plate, flatten mounds slightly, cover with plasticwrap, and refrigerate for at least 2 hours, or up to 5 days, before baking. Do not bake with warm dough because cookies will spread and bake thinner and flatter.
  • Preheat oven to 350F, line a baking sheet with a Silpat or spray with cooking spray. Place mounds on baking sheet, spaced at least 2 inches apart (I bake 8 cookies per sheet) and bake for about 6 1/2 minutes. Cookies will be at the extremely under-done point.
  • Remove tray from oven, and place a marshmallow halve on top of each cookie, pressing it down lightly into the cookie. Don’t press too hard and flatten the cookie.
  • Return baking tray to oven and bake for about 2 more minutes, until edges have set and tops are just beginning to set, even if slightly undercooked, pale and glossy in the center (hard to tell with the marshmallows covering the centers, I realize). Do not overbake because cookies will firm up as they cool. Allow cookies to cool on the baking sheet while you make the frosting.
  • For the Peanut Butter Buttercream Frosting – To a medium mixing bowl, combine the butter, peanut butter, vanilla, and whisk to combine or beat with an electric mixer until smooth.
  • Slowly add the sugar, optional salt, and mix until smooth. Based on desired consistency of frosting, add the sugar slowly, and if you’ve added too much and the frosting gets too thick, add a splash of cream or milk to thin it.
  • Add a generous dollop (2+ tablespoons) to each cookie, and smooth it, as desired, with a knife or spatula.
  • Optionally garnish with sprinkles.
  • Cookies will keep airtight at room temperature for a few days or in the refrigerator for up to 1 week. I’m okay with leaving buttercream at room temperature for a couple days; if you aren’t, refrigerate the cookies, knowing they won’t have the gooey factor. Unbaked cookie dough can be stored airtight in the refrigerator for up to 5 days, or frozen for up to 4 months, so consider baking only as many cookies as desired and save the remaining dough to be baked in the future when desired.

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Thanks for the entries in the: Chinet Bakeware Giveaway, $250 Philips Airfryer Giveaway, 3-Piece Baking Set, and Gluten-Free Dough Giveaway

Fluffernutter fan? What’s your favorite peanut butter cookie?

About the Author

Welcome to AverieCooks! Here you’ll find fast and easy recipes that taste amazing and are geared for real life. Nothing fussy or complicated, just awesome tasting dishes everyone loves!

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Please note: I have only made the recipe as written, and cannot give advice or predict what will happen if you change something. If you have a question regarding changing, altering, or making substitutions to the recipe, please check out the FAQ page for more info.

Recipe Rating


  1. My dough is super crumbly. I’m having trouble forming it into balls. Is that how it’s supposed to be?

    1. No not really…possibly you were a little heavier handed with your flour which could explain the dry or crumbly dough. And/or maybe not quite enough PB would be reasons that the dough would be on the drier side if I were to guess.

  2. Fluffernutters were a favorite of mine as a kid, and I’m seriously not sure how I missed this recipe before now. Made these, and it was success. Not overkill which was surprising, baked up like a dream, and was the perfect recipe to whip up on the end of a depressing weekend. Serious happiness!

    1. So glad you love them and that these came together great for you (and not overkill…I know, looking at the pics, one could wonder, but…it all does work out!) And hope your week gets better!

  3. These cookies were absolutely delicious! I am new to the blogosphere, and I just had to add a linkback to this recipe as one of my first post. Love your blog!

    1. Thanks for trying them – just saw your post. They looked like they turned out wonderfully & glad you loved them!

  4. Love the flavor profile , but these cookies don’t even look like they have been baked? I am a fan of u gooey middles but these look extremely under baked.

    1. Bake them until they are appropriately done in your oven, based on how you like them. Ovens, ingredients, and preferences all vary so just bake until done – whatever that means for you :)

  5. Fluffernutters were my favorite part of going to sleep-away camp. My dad never bought fluff. These cookies sound ridiculously delicious.

  6. I honestly never realized how descriptive the name “Fluffernutter”was (*facepalm*) Thanks for clearing that up. And these cookies! Holy cow! You have incorporated everything a dessert lover could want. They are to die for.

  7. These are awesome! Cookies with fluffernutter and frosting! What’s not to love here. I’m sensing a serious sugar high after having a few of these bad boys.

  8. YUM! To tell you the truth, I have never had an actual fluffernutter sandwich but have had fluffernutter baked goods. I can tell I will easily love these!

  9. Dang it Averie!! I’ve been dreaming of fluffernutters, and then I come across THIS. Now I won’t be able to stop until I actually make them!!


    You took ooey gooey wonderousness cookies and then put buttercream atop. FORREALSIES??!

    I die.

  11. I love these overloaded cookies Averie! So much peanut butter! And the marshmallow on top reminds me of a few s’more cookies I’ve made. I love melting marshmallows on top of cookies, esp peanut butter cookies! Fluffernutters remind me of my sister. They were her favorite sandwich! My mom would make me PBJ and Sarah would get fluffernutters. At times, I’d steal a bite or two of hers because I loved them too. These cookies look so moist and soft!

    1. I do love simplistic cookies, just a really solid dough that’s soft and flavorful but if I am going the trash-up route, these are the ones I want. I loved every.single.thing about them and they were dangerous to have around :) That’s a sweet story about your sister. I love family history and stories like that! And I remember some of your smores cookies now that you mention it! You went thru a cookie phase last fall/winter and were cranking them out faster than Betty Crocker :)

    1. Thanks girl! I just read your fruit salad in stealth. I wish I ate more fruit salad and less cookies :)

  12. These are downright crazy. lady, you have a penchant for chunky decadent cookies. I’ve never been a cookie person but every SINGLE one of those cookies you churn out make me crave for some. Well played.

  13. Wow girl! These look ultra decedent and you don’t have to ask me what fluff is because I totally know what it is :) I use to make a peanut butter and fluff sandwich everyday for school and survived off of peanut butter and fluff on crackers in college. I’m lucky that I had a high metabolism, because I ate tons of that stuff.
    I love all the combinations in these cookies. You’ve got the crunch, the melty chocolate from the chips and the creaminess from the fluff. Intense and yes, these will be made at some point this fall. I just need to get the kiddies back to school so I can cook again, and that isn’t until the 9th. Can you believe it? xoxo, Jackie

    1. Mine doesn’t got back til the 9th either! Or sometime that week. I have to double-check. It’s a WAYS off yet. But on some blogs I read, kids are in school starting Monday! Well before Labor Day. In MN, it was always the day after labor day as the 1st day back, no matter what.

      And yes, there’s something for everyone in these. So many elements/textures.

      And I lived off PB, Triscuits, and liquor in college & my early 20s :) We would have been a great pair with your Fluff crackers. I had my PB Triscuits daily!

  14. Oh, Averie, these look WONDERFUL! Your description was making my mouth water! Nothing beats peanut butter and marshmallow… <3

  15. Yep, these are definitely peanut buttery dreamy! I’m making these to take out on the boat next weekend. (We just got back in right now.) But boating snacks like this are the best. Throwing the fishing pole out and trolling out on the lake while eating munchies like this are my favorite! Yesterday I made your Chewy Chocolate Chip Cookies from (my most favorite, true!) your cookbook…oh my! Justin ate half the batch all ready, and he’s not even a sweet eater! Hope you’re enjoying what is left of your weekend!

    1. I am so glad to hear you made those and they were a hit! I love those cookies and they’re one of my faves, too :) And easy, right!

      You will love these Fluffernutter cookies but if you’re taking them on a boat and it’s warm out, the frosting will get pretty melty and they’re a messy cookie; not ‘stackable’ really or as portable as others, but as long as you don’t care, they’re amazing little numbers :)

      I have fond memories of boating snacks growing up in Minnesota, Land of 10,000 Lakes!

  16. I’d like a bowl of that cookie dough, a bowl of the frosting, and a spoon please:) These sound delectable!

  17. I haven’t made any fluffernutter baked goods…but I think I need to give it a try… Really soon!

  18. These cookies looks incredible Averie! What an amazing symphony of my favorite things! I’ve been meaning to make peanut butter buttercream and this seems like the perfect recipe to try it!

  19. I’ve never had fluffernutter anything, so yes, I do have loads of eating to make up for lost time. These look delicious!

  20. Oh my! These look like they are packed with everything sweet and delicious – marshmallows, peanut butter, chocolate, and frosting. It doesn’t get much better than these cookies. Pinning and making soon!

  21. Wow! If you say they’re some of your best cookies ever, they must be amazing. They look incredible, that’s for sure!!

  22. That buttercream frosting looks amazing, I would just eat it up with a spoon! Pure danger!

  23. I love how soft, moist, and thick these are! And the frosting sounds like a dream. Too good to be true!

  24. WHOA MAMA! Averie, my taste buds are going crazy at the thought of eating something this balls to the walls amazing. Paula used the word “masterpiece” to describe these cookies in her comment and I agree full heartedly. I’m going to add that you, lady, are a genius!

  25. These sound absolutely delicious. I never frost cookies out of pure laziness, but these, in bar form, with frosting? That’s what I want for my birthday “cake” next year!

    Or for, you know, any day. No birthday necessary.

    1. They’re probably the best cookies I’ve made all year, for a ‘trashed up’ cookie. I mean, it would be hard to NOT like these if we’re talking add-ins to the max.

      But for simple, basic, just dough, type of cookies, those softbatch coconut oil ones I made in the winter/spring are excellent. It’s like apples and oranges but I know you can appreciate the simple ‘just dough’ type cookies. But if you want addins, these are the ones!

      And yes, they beat bday cake, any day!

  26. Oh my. Placing a marshmallow atop a still-warm cookie! How do you come up with these brill ideas? I kinda want to shove anything sweet into my oven just so I can put melt a marshmallow on top of it. :D

  27. Fluffer nutter is one of best combos i have heard so far with Pb! We are not familiar with “fluff” in Australia but I have marshmallows, So I can make these. So cute and puffy, just like all sweet things should be

    1. Marshmallow creme or Fluff, really just melted marshmallows in a jar. It can by handy in some recipes when you don’t want to have to melt marshmallows first. So incredibly sticky that the Fluff is a nice convenience product.

      However for these, actual marshmallows are the ticket!

  28. I just made my first fluffernutter recipe last week. Oh my gosh, so good! I cannot wait to post it, but I am mean these are just over the top awesome!! I frosting, the cookies, the reese’s! It is all just wow and totally amazing!

    1. They sort of remind me of things that you do – tons of layers, flavors, and combining all kinds of elements into one. You have some cupcakes that are seriously works of art – each layer better than the next!

  29. Fluffernutter is my favorite thing on earth! These cookies look crazy good! I always put a marshmallow on top of my pb cookies and often put Reese’s Pieces in them, but I’ve never added pb buttercream. Sounds fab and love that it’s heavy on the pb.

  30. Irresistible is a word that comes to mind looking at these photos! Looooove fluffernutters, and with Reese’s I can’t imagine how amazing they are!

  31. Holy Smholy! These look sooooo ooey gooey and delicious. I am obsessed with peanut butter–any way you give it to me–so these are right up my alley. :)Your cookbook is on my “wish list” for my birthday in September. I’ve been making your honey roasted peanut butter this summer and eating it by the cupful. AMAZING!

    1. Well it’s only $13 bucks so hopefully you can pick up a copy or someone can get it for you for your bday!

      Glad you love your PB as much as I do and that the honey roasted PB has been in full rotation!

  32. Oh what a beautiful sight–these are over the top in the best way possible!!! All bases are covered with this masterpiece. I love the flourless PB and PB choc chunk cookies, but I haven’t tried a cookie of yours that I didn’t like. Picking a favorite is impossible. Hubs is going canoeing today, but bug bites and brown river water isn’t my thing. I’d much rather go for a run and bake cookies…he’d like coming home to these!

    1. Both of those cookies are amazing and I love them for just straight up eating but when I want to load a cookie with add-ins, I find that a flour-based cookie holds them better (and I get less emails about them slipping out on account of oily dough) so I went with these. If I was making the recipe just for me, I probably would have used my PB Choc Chunk Cookie recipe but cest la vie :) Your hubs would LOVE coming to home to these – who wouldn’t. lol And canoeing and bug bites..omg yes. Growing up in rural MN (land of 10,000 lakes), I am very, very familiar with canoeing, humidity, huge bugs and by this time of the summer, the mosquitoes are as big as golf balls!