Homemade Marshmallow Buttercream Frosting Recipe

marshmallow buttercream frosting recipe pop shop america

Homemade buttercream icing is delicious, and even more so when you start playing with the flavors. I love marshmallow flavor; in fact, this marshmallow buttercream frosting was inspired by my favorite coffees – Peppermint Mocha with Marshmallow Latte.

Use this homemade buttercream to top any bakery item that would be oh-so-good with a hint of marshmallow flavor; scroll to the bottom of this post for some great ideas! My favorite way to use it is hands downs on these S’mores Cupcakes.

piping swirl of marshmallow icing onto cupcakes

This scrumptious Marshmallow Buttercream makes enough to frost 12 cupcakes or a single layer cake. Double butter, powdered sugar and marshmallow crème for a layered cake or 24 cupcakes. (Milk will still be added as needed, but you will probably not need double the milk. Just be sure to add a tablespoon at a time.)

four s'mores cupcakes with marshmallow frosting

Ingredients for Marshmallow Buttercream Frosting

You’ll need to gather:

  • 1 stick (1/2 cup) unsalted butter, room temperature
  • 1 ½ cups powdered sugar, sifted
  • 2-4 tablespoons milk
  • ½ cup marshmallow crème (sometimes called marshmallow fluff)

The only specialized equipment you’ll need is a stand mixer or a quality hand mixer. 

Making the Marshmallow Buttercream Frosting

Make sure your stick of butter is room temperature, but not melting. In the bowl of a stand mixer, whip the butter with the whisk attachment until it is light in color and fluffy, about 3-4 minutes.

butter in mixing bowl for buttercream

Sift the powdered confectioners’ sugar. Add the powdered sugar to the butter, ½ cup at a time. Add ½ cup of powdered sugar and mix on low for a moment to stir in the sugar. Then increase the speed to high to whisk in the powdered sugar into the butter. Repeat 2 more times with the rest of the powdered sugar.

whip powdered sugar with butterfor frosting

Measure in ½ cup of marshmallow crème and stir on medium until combined and reasonably stiff.

marshmallow fluff for homemade buttercream

You want it to stay on the cupcake and not run off, so you need the frosting to be thick. If it’s too thick, add milk a tablespoon at a time. If it’s too runny, add sifted powdered sugar, ¼ cup at a time.

marshmallow buttercream icing on mixer

When the frosting has reached the consistency you like, spoon into a piping bag or zip top bag fitted with a piping tip. Decorate cupcakes with frosting.

Note: Your frosting may be just a bit softer than a typical stiff buttercream. The marshmallow makes it slightly softer. I recommend piping frosting shortly before serving, in order to preserve the look and stiffness of the frosting.

bowl of marshmallow buttercream icing

Tips and Tricks for the Perfect Buttercream

Room Temperature Butter – cold butter will not whip well, because it’s too hard. If your butter is beyond room temperature and too warm, it can make your frosting runny.

Sifted Powdered Confectioner’s Sugar – your powdered sugar most likely says ‘pre-sifted’ on the package, but you absolutely should sift it freshly, right before you make the frosting. This adds air and makes the powdered sugar fluffier, which ultimately makes the texture of your frosting much better.

My Butter is Melting/My Frosting Seems Runny Because of Soft or Melted Butter

if your frosting is taking you too long to make or you’re making it in a very warm kitchen, the butter may get a bit too soft or melted in your frosting mixture. To fix this, place your mixing bowl in the refrigerator for 15 minutes or so, then remove and continue making your frosting.

piping marshmallow buttercream onto smores cupcake

Storing Unused Frosting

Refrigerator – You can store any leftover marshmallow buttercream frosting in the refrigerator for up to 5 days. Place frosting in an airtight container or zip top bag.  Let it come to room temperature before attempting to pipe the frosting.

Freezer – Freeze unused marshmallow buttercream frosting in the freezer in an airtight container for up to 3 months. Thaw frosting in refrigerator. Let come to room temperature, then add to the bowl of a stand mixer and whip to fluffiness before piping.

closeup marshmallow buttercream icing

Ideas for Using Marshmallow Buttercream Frosting

The absolute best way to use this marshmallow buttercream frosting is on these S’mores Cupcakes. Pipe or spread the marshmallow buttercream onto the cooled cupcakes, then decorate with chopped chocolate, graham cracker crumbs, and mini marshmallows or marshmallow bits (the crunchy little marshmallows in hot chocolate – sold in a container).

This marshmallow buttercream would also be delicious on a chocolate fudge cake, or a peppermint chocolate cake.

Sandwich this buttercream between sandwich cookies. Any kind would work – chocolate, vanilla, chocolate chip sandwich cookies, etc.

My son likes frosting on graham crackers as a special – and quick and easy – treat, and homemade marshmallow buttercream on a honey graham cracker is delicious!


piping swirl of marshmallow icing onto cupcakes

Scrumptious Marshmallow Buttercream Frosting

Servings 12 servings


  • 1 stick (1/2 cup) unsalted butter, room temperature
  • 1 1/2 c. powdered confectioners sugar, sifted
  • 1/2 c. marshmallow creme (also known as marshmallow fluff)
  • 1-4 tbsp. milk


  • In bowl of stand mixer, whip butter with whisk attachment until light and fluffy, 3-4 minutes.
  • Sift powdered sugar. Add to butter, 1/2 cup at a time. Mix in slowly then increase speed to high to whip.
  • Measure 1/2 cup marshmallow creme and stir on medium until combined and thick.
  • If frosting is too thick, add milk 1 tablespoon at a time. If it's too thin, add powdered sugar, 1/4 cup at a time until frosting reaches desired consistency.


Note: Frosting may be just a bit softer than a typical stiff buttercream, due to marshmallow creme.  I recommend piping frosting shortly before serving, in order to preserve the look and stiffness of the frosting.

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