Toasted Marshmallow Buttercream Frosting

Toasted Marshmallow Buttercream Frosting

This frosting is SO fun!  It’s Toasted Marshmallow Buttercream Frosting…with toasted marshmallows mixed right into the buttercream.  The toasted marshmallows give the frosting a delicious flavor and marshmallow texture!  Perfect for cake filling or cupcake frosting!

So this frosting. I’m just gonna say that’s it’s insanely delicious.  Not because I made it.

Well, maybe that. But because how did I not think of this sooner? And I didn’t Google it because I would like to go on believing I invented it. And Google is an inventors dream-killer.

But anyway it’s so super simple I can’t take it… it’s buttercream frosting recipe, with toasted melty marshmallows mixed right in.

Duh, right?

The marshmallows give it an insanely yummy flavor, but also a cool texture!  Like a cross between marshmallow and frosting, which obvi… it is. Of course, piped some on top of a vanilla cupcake and sprinkled Rice Krispie Cereal, because Rice Krispies are my love language.

But I could totally get down with this on a chocolate cupcake with graham cracker crumbs sprinkled on top. S’mores, FTW!

So let me show you…Toasted Marshmallow Buttercream Frosting…

Toasted Marshmallow Buttercream Frosting

Just mix up a basic buttercream.  You’re gonna go a little lighter on the sugar because the marshmallows add sweetness.

Toasted Marshmallow Buttercream Frosting

Then spread marshmallows on a parchment lined baking sheet…

Toasted Marshmallow Buttercream Frosting

And toast them under the broiler for just about 45 seconds, until they look like this…

Toasted Marshmallow Buttercream Frosting Immediately mix that right into the frosting.

Toasted Marshmallow Buttercream Frosting

And beat the heck out of it!

Let it cool a bit before piping or spreading.  You’re gonna LOVE the texture of this frosting.

And it works perfect as a filling to a cake!


As it cools it will stiffen up, so don’t go adding a bunch more powdered sugar!



Toasted Marshmallow Buttercream Frosting


  • 1 cup butter, room temperature
  • 4 cups powdered sugar
  • 2 Tbsp milk
  • 10 oz mini marshmallows


  1. In bowl of stand mixer beat butter until smooth. Add in powdered sugar slowly and then milk and continue mixing until smooth.
  2. Turn oven onto broil. Line a baking sheet with parchment paper and spread marshmallows out in an even layer. Place under broiler for about 45 seconds until they are browned and puffed. Watch closely because they will burn very quickly.
  3. Immediately scrape the marshmallows in to the butter mixture and beat until smooth.
  4. The frosting will be warm due to the marshmallows, so allow it to cool completely before spreading or piping.


60 Responses

  1. Dalila G.

    What a wild and fabulous idea!!
    As far as I’m concerned, you invented this frosting, I’m NOT going to Google it, that’s my story and I’m sticking to it. 🙂
    I will be trying this recipe for marshmallow/buttercream icing this weekend on my cupcakes, thanks Shelly!

  2. Leanna R

    You have me thinking. I made some peppermint marshmellows at Christmas and have some left (why?). Anyway cut them up and toast them. They are pink, too……….

  3. Amy B

    Perfect timing. I have been looking for the “right” frosting to put on top of oreo cupcakes (made with the new rice krispy marshmellow oreos). This will be perfect!

  4. Amy

    Hi there, I’m making your perfect funfetti cake with this frosting and the sprinkle streusel topping for my best friend’s daughter’s first birthday party tomorrow! I’ve just finished making this frosting but it’s very goopy, definitely doesn’t seem like it would be useful for piping at all and I’m worried it will just drip outside the cake if I try and put it between the two layers. Any advice? Followed directions to a T but I’m in Ireland and I’m wondering if the marshmallows here might not be exactly the same as the ones from the States so maybe they reacted differently to being toasted? It tastes DELICIOUS but I’d hate to start frosting the cake and have it ruin that by spilling all along the edges…

    Was also wondering, since I’m asking another question already, what do you think about putting the streusel between the cake layers too, on top of the frosting? Instead of just sprinkled on the top of the cake?


    1. Shelly

      Very strange.. as the filling cools (the marshmallows) it will thicken back up, but if you’re worried, add a bit more powdered sugar!

  5. Lauren

    Every time I make this frosting it is just so runny. I even put it in the freezer for an hour.
    So disappointed because it certainly tastes amazing.
    Maybe it’s the humidity here in Houston? I mean there’s never a day when it’s less than about 95% humidity.

    1. Lauren

      I made moist double chocolate cupcakes and made this frosting for the top along with crushed Graham crackers. It is amazingly delicious- tastes just like a fresh roasted marshmallow! I am in love.

      One thing I did was cut back on the powdered sugar. I always dislike basic recipes that use 4 cups. I think it’s overkill on sweetness, hides flavors, and it’s always too much for just 12 cupcakes. I used about 2 cups powdered sugar and a bit less butter. I still used the full 10 oz. of toasted marshmallows cause I wanted a strong flavor to shine and not be overpowered by the cake. It came out a bit goopy, as to be expected with less powdered sugar, but I used a little bit of corn starch to stiffen a bit. I piped my cupcakes and let them set for about an hour. The frosting stiffened beautifully and everyone was losing it over the flavor. I believe this way you have a much stronger flavor that doesn’t get lost in too much sugar. Such a great idea! Thank you!

  6. Nancy KV

    Truly perfection! I made this frosting to fill some vanilla macarons for my brunch yesterday. It’s genius! The toasted bits are fantastic. Thank you for the awesome recipe!

  7. Michelle

    OH MY AWESOMENESS!!!!!!! This buttercream is the BOMB!!!!!!!!!!! Thank you so much for creating this and sharing it with all of us!!!!


    1. Shelly

      I don’t recommend refrigerating it…the consistency will definitely change due to the marshmallows in it. It sets up and will be tough to get back to spreadable.

  8. Ana

    I made this icing last night and oh my goodness it is so good! I love the crunchiness of the marshmallows and the light flavor of this icing. It’s hard not to eat it by the spoonful!

  9. Azza

    Hi. Can I color this frosting – using gel paste? If yes, at what stage (before OR after adding/mixing the marshmallows into the buttercream?).

    Another question, is there a recommended temperature for broiling the marshmallows? As per your instructions above, just turn on the oven and put the marshmallows in..


    1. Shelly

      The broil setting on my oven is 550°F I believe. Also I have never colored this frosting, but would add the coloring before adding the marshmallows, into the butter/powdered sugar/milk mixture and mix it until it’s a uniform color. When you add the marshmallows just mix them until the color is uniform!

  10. Kristee

    Hey! Great idea!! This looks really delicious! Can’t wait to try it out this weekend! May I know the life shelf of this toasted marshmallow frosting?((:

  11. Jennifer

    This is really yummy AND easy! I just had a slight problem. It nearly wrecked my kitchenAid hand mixer because the marshmallows stuck themselves right up the beaters and into the holes that hold the beaters as I beat. I would recommend using a stand mixer. Other than that, yum!

  12. Abby

    I made this frosting today and it’s delicious however once it cooled it has become so sticky and thick that it is impossible to pipe. I hade to empty the piping bag and make a sloppy icing mess with a knife instead. Any suggestions?

  13. Mine came out incredibly sticky & difficult to manage, does anyone have any hints or tricks as to what went wrong and how to correct it next time I give this recipe a whirl? I’d like to stay away from adding more powdered sugar, as the recipe as written is already very sweet.

  14. Brit

    This sounds incredible! I’m going to use it to make s’mores cupcakes. I’ve recently been introduced to Swiss meringue buttercream, and I love it. Do you think this would work with that too?

  15. Bethany

    I wanted to love this buttercream so bad! The second I put the marshmallows in it melted everything to mush. Followed there recipe to a T.

    1. Shelly

      Yes, the marshmallows are warm, but as you beat it, it will thicken up, and it does say to wait until it cools to spread or pipe!




  19. Shelby

    As soon as I put the marshmallows in it completely melted my buttercream and ruined it! Cant have fluffy buttercream with melted butter! Now it just looks like runny icing sugar. Going to try letting the marshmallows sit for a bit before mixing in next time.


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