Stuffed Fluffernutter Cookies

12 cookies
45 min

These Stuffed Fluffernutter Cookies have a soft peanut butter dough filled with creamy peanut butter and gooey marshmallow. The dough gently cracks open to expose the marshmallow!

These cookies are TO die for. They're just slightly crisp on the edges, and the rest of the cookie is oh so soft. Let's not forget the chewy marshmallow strewn throughout the center, and bits of the peanut butter provide an extra punch of flavor.

Adam asks me every other day to make them. Adam's brother was in town after a test batch and he ate eight of them in about 12 hours. These cookies are not small, by the way. My sister also demanded the recipe before this publish because she couldn't wait to make them.

Stuffed Fluffernutter Cookies have rave reviews thus far - you're going to love them!

What does fluffernutter mean?

This post contains affiliate links. As an Amazon Affiliate, I earn from qualifying purchases.

Do you know what a fluffernutter is and did you grow up eating this as a child? If you're lost here, a classic fluffernutter is a sandwich made from squishy white bread, filled with peanut butter and marshmallow fluff. If you had this tub in your cupboard, welcome to the fluffernutter club.

It is THE best treat - my mom still makes them occasionally for her and my dad. So cute. I can also distinctly remember spreading dabs of peanut butter and fluff on saltine crackers at my grandparents house.

Peanut butter and marshmallow

A perfect combination, these cookies are made with creamy peanut butter (Jif, Skippy, Peter Pan, not natural peanut butters) and a whole marshmallow rather than marshmallow fluff. This is simply because a stuffed cookie is easier to assemble around a more stiff ingredient! That's also why the peanut butter gets frozen before going into the cookies. Check the FAQ section below for more information on marshmallows vs marshmallow fluff.

Making the cookies

Start by adding 12 heaping teaspoon dollops of peanut butter onto a parchment lined plate and freeze. Freezing these makes life SO much easier when stuffing the cookies. Use your finger or a butter knife to get the peanut butter out of the teaspoon. If the ¼ cup does not yield the 12 teaspoons, use additional peanut butter to get to 12. It should be very close.

While the peanut butter is in the freezer, make the cookie dough. Sift or whisk together the flour and baking soda and set aside. Cream together the butter and peanut butter, then add the sugars and beat on medium speed for about two minutes until it becomes lighter and fluffier. This can be done with a stand mixer (paddle attachment) or a hand mixer.

Add in the egg, salt and vanilla, then scrape down the sides and add the flour. Mix on low until it's just incorporated.

Assembling and stuffing the cookies

Line two standard baking sheets with parchment paper and gather 12 marshmallows. Rip a section of 3-4 frozen peanut butter dollops off of the plate - it's best to work in batches so the peanut butter stays as hard as possible while assembling the cookies.

Remove three even tablespoons (~60g) of dough and press it between the palms of your hands until it's flat and even. Place one dollop of peanut butter in the center, then lay a marshmallow (on its long side) on top.

Work the dough upwards and around the top of the marshmallow until it’s completely sealed. The dough may crack in some places - just gently push it together with your thumbs as best as possible. Place the ball seam side down on the cookie sheet and stud with peanut butter chips (optional).

Repeat the process until you have 12 cookies. Evenly space them out between the two cookie sheets, 6 per sheet. Bake one sheet at a time in a preheated 350℉ oven in the middle rack for 9-11 minutes. The edges and tops will look barely brown, so take care not to overcook them!

Remember, it's just a small amount of dough since it's been flattened out, so it doesn't need much time to fully cook. They will still look sightly puffy, but will flatten out while cooling. The marshmallow should still be gooey - if it has disintegrated, they're likely overcooked.

Immediately upon removing the cookies from the oven, use the tines of a fork to push together any bulging parts of the cookie into an even circle. Top with flaky salt if you have some! Allow the cookies to cool completely on the pan. Once cool, a spatula may be needed to lift off some sticky marshmallow pieces when transferring to a plate or storage container.


Can I substitute marshmallow fluff for marshmallows?

Not in this recipe! This is for a couple of reasons:

  • The cookie dough needs the structure of the marshmallow to completely wrap around. Fluff is too soft to turn this into a stuffed cookie (at least, a non messy stuffed cookie).
  • The marshmallow takes longer to melt which gives the cookie time to cook before "cracking" open to show the gooey marshmallow.

What is marshmallow fluff made of?

Marshmallows and marshmallow fluff are almost identical in terms of ingredients. Both of these contain egg whites, sugar syrups, and vanilla. The only notable difference is that marshmallows have gelatin added, which is why they have a firmer texture. There is also a bit of a difference in the mixing process that gives fluff an airier texture than a marshmallow. BUT, same base ingredients.

Can I use mini marshmallows instead of large marshmallows

Yes. While it is recommended to use normal-sized marshmallows to make the Stuffed Fluffernutter Cookies, if you only have mini marshmallows available, use 4-5 per cookie.

Searching for more peanut butter recipes?

  • Chocolate Peanut Butter Tart
  • Peanut Butter Banana Oatmeal Bars
  • Peanut Butter Cookie Dough Bites
Stuffed Fluffernutter Cookies
Recipe details
  • 12  cookies
  • Prep time: 30 Minutes Cook time: 15 Minutes Total time: 45 min
Show Nutrition Info
Hide Nutrition Info

  • 1/2 cup unsalted butter room temperature (113g)
  • 1 cup creamy peanut butter divided (250g), Jif/Skippy/Peter Pan (not natural)
  • 1/2 cup light brown sugar 100g
  • 1/3 cup granulated sugar 67g
  • 1 large egg room temperature
  • 1 teaspoon vanilla paste or extract
  • 1/8 teaspoon kosher salt
  • 1 teaspoon baking soda
  • 1 1/2 cups all-purpose flour 180g
  • 12 marshmallows standard size
  • Peanut butter chips optional
  • Flaky sea salt optional

Lay a piece of parchment paper over a standard sized plate. Measure out ¼ cup (~63g) of peanut butter, then use a teaspoon measure to scoop heaping scoops onto the plate. You will need 12 dollops. Use more peanut butter to get to 12, if needed. Place the peanut butter in the freezer while preparing the dough.
In a bowl, whisk together the flour and baking soda and set aside.
In a stand mixer fitted with the paddle attachment, cream together the butter and ¾ cup peanut butter, then add the brown sugar and granulated sugar and beat on medium speed for 2 minutes.
Add the egg, vanilla, and salt and mix to combine, then scrape down the sides. With the mixer on low speed, add the flour and mix until just incorporated.
Prepare two full sized cookie sheets with parchment paper and preheat the oven to 350℉.
To stuff each cookie, measure out three even tablespoons (~60g) of dough then flatten it out in between your palms. Place one dollop of the frozen peanut butter in the center, then add a marshmallow (on its long side) on top. Work the dough upwards and around the top of the marshmallow until it’s completely sealed. The dough may crack in some places - just gently push it together with your thumbs as best as possible. Place the seam side down on the cookie sheet.
Repeat this until there are 12 cookie dough balls. It's best to work in batches of 3 or 4, leaving the extra peanut butter in the freezer. I just rip the amount needed per batch off of the parchment sheet. Arrange the cookies, 6 on each pan, and stud each top with 4-5 peanut butter chips, if desired.
Bake one pan at a time for 9-11 minutes on the middle rack until the edges are set and just barely brown on the very bottom edge. You also want the cookie to slightly break open to expose the marshmallow (see notes section). If the Remove from the oven and use a fork to gently push the cookies into nice circles. Then, top with flaky salt, if desired.
Let cool completely on the pan before transferring to a serving platter or storage container. You may need to use a spatula to lift off some of the sticky marshmallow pieces.
  • It can be slightly difficult to tell when these cookies are done. There will be just the slightest tinge of brown around the edges near the bottoms. The cookies should have started to crack open to expose the marshmallow (but not all of them will always crack) and they will still look slightly puffy. This is what you're looking for. If they are still ball-like, continue baking, checking every minute. If the marshmallow has disintegrated, they have been overcooked.
  • Store in a sealed container for up to three days.
  • To freeze, fully assemble and flash freeze on a cookie sheet for 30 minutes then transfer to a zip top bag. To bake the cookies frozen, bake in a preheated 350℉/177℃ oven for 15 minutes.
The Cozy Plum | Callan
Want more details about this and other recipes? Check out more here!