Toasted Marshmallow Frosting

The only thing better than a toasted marshmallow is this toasted marshmallow frosting! Most marshmallow frosting recipes use marshmallow cream or melt marshmallows before incorporating them, and then the frosting may be toasted later. But toasting the marshmallows before adding them to buttercream not only provides us with more of that yummy roasted flavor, it adds a delightful texture to this marshmallow frosting. You may find yourself taste-testing this recipe a lot, it’s so good!

I use this marshmallow buttercream frosting to fill my S’mores Cookie Sandwiches, but you could also use it to top Chocolate Cupcakes, graham crackers, or in place of marshmallow cream on my S’mores Brownies. It’s basically delicious on everything!

Why This Recipe Works

• Easy marshmallow frosting. Making buttercream is a breeze, and toasting the marshmallows takes less than two minutes. 
• Perfect for making in advance. You can make this marshmallow buttercream a couple of days in advance, so you can break down your baking in small increments and make things easy on yourself. 
• Versatile frosting. Use this homemade marshmallow frosting recipe on whatever you like! I think it pairs best with chocolate or graham cracker-based baked goods because it makes me think of s’mores, but frankly, I think this frosting would be good with pretty much anything!

Ingredient Notes

• Mini marshmallows: Some marshmallow frosting recipes use marshmallow cream. This is a marshmallow frosting using marshmallows. Using toasted marshmallows provides a scrumptious toasted flavor and subtle texture to the frosting. Make sure to use mini marshmallows, as large or regular marshmallows won’t break down into the frosting as well. 
• Unsalted butter: It isn’t a buttercream without butter! Unsalted butter is one of the important building blocks for this frosting, and using unsalted vs salted butter allows us to control the saltiness. 
• Powdered sugar: The other building block for buttercream; powdered sugar doesn’t just add sweetness but also structure to frosting. 
• Heavy cream: Adding heavy cream to frosting keeps it rich and creamy while also helping it not be too sweet. By beating heavy cream in with the other buttercream ingredients, we’re also able to incorporate a little more air for fluffy marshmallow frosting. 
• Salt: To counteract the sweetness of both the marshmallows and the powdered sugar, a pinch of salt goes a long way. 
• Vanilla extract: The base flavor of marshmallows is vanilla, but adding additional vanilla extract to this marshmallow buttercream recipe really makes the flavor shine.

How to Make Marshmallow Frosting

1. Prep oven and pan. Spray a baking sheet with nonstick spray and set your oven to broil. 
2. Toast marshmallows. Spread 3 cups of mini marshmallows in an even layer on the prepared pan. Pop the marshmallows in the oven. These will toast REALLY quickly, so keep an eye on them. Mine were toasted in less than two minutes. Remove them from the oven and set them aside to cool. You can turn off your oven. 
3. Beat butter for buttercream. Add 1½ cups of unsalted, slightly softened butter to the bowl of a stand mixer with the paddle attachment. You can also use a large bowl and an electric mixer. Beat the butter until it is light-colored and smooth.

4. Add marshmallows and salt to butter. Add a pinch of salt and your toasted marshmallows to the mixing bowl and beat until the marshmallows are evenly distributed throughout the butter. 
5. Add remaining ingredients to butter mixture. Pour 1 teaspoon of vanilla extract into the stand mixer bowl. With the mixer on low, slowly add 4 cups of powdered sugar, followed by one tablespoon of heavy cream. 
6. Mix ingredients on high speed. Once all of the ingredients have been added, use a rubber spatula to scrape the bottom of the bowl, then beat the buttercream on high speed for 3 minutes. 
7. Use or store immediately. Use toasted marshmallow frosting for cake, brownies, and cookies, or eat it with a spoon. Or, store it in the refrigerator to use later.

Recipe Tips

Don’t burn your marshmallows! If you’re worried about leaving them in the oven too long, a culinary torch could be a good option. On the flip side, if you prefer your marshmallows a little burnt, then I guess you could toast them a little extra for this recipe. 

Besides the addition of the toasted marshmallows, this is a pretty basic buttercream recipe that I think could take adaptations well. Add a tablespoon or two of cocoa powder for chocolate marshmallow frosting, peanut butter for peanut butter marshmallow frosting, or even maybe some raspberry jam or freeze-dried strawberries for a berry marshmallow frosting.

If you store this frosting in the fridge, you’ll need to let it come to room temperature for 4-5 hours before so it becomes soft and spreadable again.

Make Ahead, Storing, and Freezing

Make Ahead: This frosting can be made several days before you need to use it. Just follow the storage instructions.

Storing: Store toasted marshmallow buttercream in an airtight container in the fridge for 5-7 days. This recipe makes around 4½ cups of frosting. If you’ve frosted something like cupcakes or cookies with this frosting, I recommend storing the frosted goodies in the fridge as well because of the heavy cream in the frosting.  

Freezing: Yes, this frosting can be frozen! Store it in an airtight container in the freezer for up to 1 month. Before using, let it thaw in the fridge overnight, then come to room temperature. You will need to re-whip it to get the right consistency.

For more information on storing and freezing buttercream as well as decorated cakes and cake layers, check out my How to Store and Freeze Cakes guide!

Recipe FAQs

More Frosting Recipes

• Lemon Buttercream
• Brown Butter Buttercream
• Biscoff Buttercream
• Nutella Frosting
• Swiss Meringue Buttercream
• Chocolate Frosting