Bars + Brownies

Marshmallow Brownies with Peanut Butter #26

Monday, September 14, 2020

Marshmallow Fluff + Peanut Butter + Brownies = Yes, please.

And you don’t need any kind of mixer to these – just a bowl and a whisk! 

Marshmallow Brownies with Peanut Butter  are a combination of rich and chewy, chocolatey brownies with marshmallow fluff and a peanut butter filling swirled throughout the top.

From 100 Cookies

Notes This recipe is a variation on My Favorite Brownies recipe.
This version I actually prefer the day after they’re made, as the marshmallow fluff softens and the chocolate flavor intensifies.

Marshmallow Peanut Butter Brownies

Peanut Butter Marshmallow Brownies

Servings: 24 brownies
Prep Time: 15 minutes
Cook Time: 30 minutes
Total Time: 45 minutes
The perfect brownies swirled with marshmallow fluff and peanut butter! Easy to make and are a great brownie recipe to make for parties.
Sarah Kieffer
5 from 1 vote
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  • Adjust an oven rack to the middle of the oven. Preheat the oven to 350F [180C]. Grease a 9 x 13 in [23 by 33 cm] baking pan and line with a parchment sling.
  • In a medium bowl, mix together the peanut butter, sugar, butter, vanilla, and salt until combined and completely smooth.
  • Make the brownie batter as directed (but do not bake it!). Pour the brownie batter into the prepared pan. Dollop the peanut butter filling and the marshmallow cream over the top, alternating the two. Drag the tip of a butter knife through the batter, creating swirls.
  • Bake until the sides of the brownies have set, the top is starting to crackle and look glossy, and a wooden skewer or toothpick inserted into the center comes out with crumbs, 26 to 32 minutes. The batter on the toothpick should not be wet but should have a good amount of crumbs clinging to it. Transfer the pan to a wire rack and let cool completely. Use the parchment sling to gently lift the brownies from the pan.
  • Cut them into bars and serve. Store the brownies in an airtight container for up to 3 days.


  • Reply
    Friday, July 30, 2021 at 5:22 am

    5 stars
    Loved by the whole family!

  • Reply
    Friday, October 30, 2020 at 8:19 am

    Really great idea. Thank you.

  • Reply
    Thursday, September 17, 2020 at 4:42 pm

    What could you use instead of peanut butter in this recipe? Thanks!

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