Peanut Butter Fluff Filling for Whoopie Pies

This is a simple easy filling for cookies. The problem with regular marshmallow for a cookie filling is the top cookie will slide off. My grand kids insist on marshmallow fluff for their whoopie pies and after pies sit on a plate they slide all over the place and they get sticky. One of the solutions is to add peanut butter to the fluff. It has been a couple of hours and they have not slid off. I have one grandchild that can’t have peanut butter and he was my whoopie pie assistant tonight, so the fall whoopie pies was made later with the peanut butter fluff filling.

I used my fall and star whoopie pie baking sheets to make them. I like to put the fall shaped cakes on top of a regular round whoopie pie. It lets the peanut butter fluff show. I wanted to share this recipe because I did a quick search for it on the internet and did not find this simple recipe. It makes such a good cookie filling.

Peanut Butter Fluff Filling for Whoopie Pies

  • Difficulty: easy
  • Print


  • 1 cup creamy peanut butter
  • 2 cups marshmallow fluff


Heat peanut butter for 30 seconds in a microwave. You only want to soften it and be warm. In a bowl place 2 cups of marshmallow fluff. It will be sticky so you will need a spatula. Quickly pour the soft warm peanut butter on top of marshmallow. Use spatula to fold it in. You don’t want to over mix, just gently fold until mixed.

Spread filling between whoopie pie cakes by dropping a tablespoon full first on the bottom cake. Gently spread the filling in a circle. Place top on and gently push down. The pie should stay together nicely.

8 Comments Add yours

  1. Jyo says:

    Awesome and yummy bites !

    Liked by 1 person

  2. Sheryl says:

    I never would have thought of making a peanut butter filling for whoopie pies. It sounds wonderful.

    Liked by 1 person

    1. trkingmomoe says:

      I got the idea from a cooking show. They were making peanut butter fluff for another kind of cookie. Only they made the marshmallow fluff from scratch. I just remembered they warmed up the peanut butter to soften it before folding it in. It has been a few days since I made them and the fluff is still in place. Regular fluff would have slid off the whoopie pie by now. The peanut butter must give the fluff structure. It does make the whoopie pies special. Thanks for taking time to comment.


  3. Mmmmmmmmmm! These sound wonderful!

    Liked by 1 person

    1. trkingmomoe says:

      I have some fluff left over so I will probably make some peanut butter cookies and use the rest of the fluff. I hope you are doing well in your new home. You have had some big life changes this past year. Thanks for taking time to comment.

      Liked by 1 person

  4. JZ says:

    Oh these look delicious!

    Liked by 1 person

    1. trkingmomoe says:

      Thanks for stopping in and making a comment. They were really good.

      Liked by 1 person

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