- 2/3 cup all purpose flour
- 1 teaspoon baking soda
- Pinch of salt
- 8 tablespoons butter, room temperature
- 1 cup creamy peanut butter (well-stirred if using natural)
- 1 1/3 cups light brown sugar
- 1 egg, room temperature and lightly beaten
- 1 teaspoon pure vanilla bean paste or extract
- 2 tablespoons to 1/4 cup marshmallow fluff (depending on how much you add to each cookie)
- In a medium bowl, whisk together flour, baking soda, and salt.
- In a stand mixer fitted with a paddle attachment, combine butter, peanut butter and brown sugar and beat on medium speed until well combined.
- Add egg and vanilla and beat to combine.
- Add dry mixture and beat again to combine until you have a thick dough.
- Cover the bowl with plastic wrap and place in the fridge for at least 30 minutes, preferably up to 1 hour.
- Preheat oven to 375°F. Prepare two baking sheets with nonstick silicon mats or parchment paper and set aside.
- Grab a medium cookie scoop and fill it halfway with dough, pressing it into the bottom and up the sides. Spoon a teaspoon of marshmallow fluff into the center, and then top with more dough to fill the scoop. Place each ball of dough on prepared baking sheets, with no more than 6 on each, evenly spaced out with plenty of room for the cookies to spread.
- Bake for 8-9 minutes until the cookies have spread and started to crinkle on top. Remove from the oven and let cookies cool for at least 15 minutes on the baking sheet itself – they will continue to spread and set a bit more as they cool. Carefully move to wire racks to cool completely. Enjoy!
- Store cookies for up to a week in an airtight container, with parchment paper between layers.
- The butter needs to be room temperature. If you use cold butter, they’re puffier. If you use melted butter, you end up with a thin and crispy mess.
- They need to be 100% light brown sugar, not a combination of granulated and brown sugar.
- If you find the dough needs a little more flour to work with it, you can use up to 3/4 cup all purpose flour and get similar results.
- Chilling the dough is essential.
Keywords: fluffernutter cookies, peanut butter cookies, peanut butter and fluff, peanut butter fluff cookies, marshmallow fluff cookies, marshmallow cookies