Marshmallow frosting is a light, billowy topping that brings a cloud-like sweetness to cakes, cupcakes, and cookies. With a glossy finish and a subtle vanilla flavor, it’s a favorite for anyone seeking a frosting that’s less heavy than buttercream but still decadently sweet. This classic recipe is easy to master and delivers a perfectly smooth, pipeable texture every time.
Ingredients
- 4 large egg whites, at room temperature
- 1 cup (200g) granulated sugar
- 1/4 teaspoon cream of tartar
- 1/8 teaspoon fine sea salt
- 1 teaspoon pure vanilla extract
Instructions
- Prepare your equipment: Ensure your mixing bowl and whisk are clean, dry, and free from any grease. Any fat residue can prevent the egg whites from whipping properly.
- Set up a double boiler: Fill a medium saucepan with 1 inch of water and bring it to a simmer over medium heat. Place a heatproof bowl (preferably metal or glass) on top, making sure it doesn’t touch the water.
- Combine ingredients: In the heatproof bowl, combine the egg whites, sugar, cream of tartar, and salt. Whisk continuously until the sugar dissolves and the mixture is warm to the touch (about 160°F/71°C), 3–5 minutes. You can check by rubbing a little between your fingers—it should feel smooth, not gritty.
- Whip the mixture: Remove the bowl from the heat and immediately transfer to a stand mixer fitted with the whisk attachment (or use a hand mixer). Beat on high speed until stiff, glossy peaks form and the bowl feels cool to the touch, about 5–7 minutes.
- Add vanilla: Add the vanilla extract and whip just until incorporated, about 10 seconds more.
- Use immediately: The marshmallow frosting is now ready to spread or pipe onto your cooled cakes, cupcakes, or cookies.
Tips
- Substitutions: If you don’t have cream of tartar, you can use 1/2 teaspoon of lemon juice or white vinegar to help stabilize the egg whites.
- Flavor variations: Swap out the vanilla extract for almond, coconut, or peppermint extract to change up the flavor. Start with 1/2 teaspoon and adjust to taste.
- Common mistakes: Avoid getting any yolk in your egg whites and ensure the bowl is grease-free; even a small amount of fat can prevent stiff peaks from forming.
- Storage: Marshmallow frosting is best used immediately, but leftovers can be stored (see below). It may lose some volume over time.
Serving Suggestions
- Classic cupcakes: Pipe generous swirls atop chocolate, vanilla, or red velvet cupcakes, then toast lightly with a kitchen torch for a s’mores-inspired treat.
- Layer cakes: Frost between layers of chocolate or banana cake for a fluffy, marshmallowy contrast to dense cake textures.
- Cookies: Use as a filling for sandwich cookies, whoopie pies, or homemade oatmeal cream pies.
- Dessert dips: Serve as a dip for fresh strawberries, graham crackers, or pretzels at parties.
Variations
- Chocolate marshmallow frosting: Fold in 1/4 cup sifted unsweetened cocoa powder after whipping for a chocolatey twist.
- Toasted coconut: Gently fold in 1/2 cup toasted coconut flakes for flavor and texture.
- Lemon marshmallow frosting: Replace half the vanilla with fresh lemon juice and add 1 teaspoon finely grated lemon zest for a citrusy version.
- Colored marshmallow frosting: Add a few drops of gel food coloring once the frosting is whipped for themed desserts.
Storage and Reheating
Marshmallow frosting is at its fluffiest immediately after making, but it can be stored if needed. Place leftover frosting in an airtight container and refrigerate for up to 2 days. Before using, let it come to room temperature and re-whip briefly with a mixer to restore some volume and smoothness. Note: The frosting may lose some of its glossy texture and airy consistency after storage, but it will still be delicious.
This frosting is not ideal for freezing, as the texture can become weepy or grainy once thawed. For best results, make only as much as you need and use immediately.
Frequently Asked Questions
- Can I use pasteurized egg whites from a carton?
- While some brands of pasteurized egg whites can be whipped, many do not achieve stiff peaks as reliably as fresh egg whites. If you choose to use them, check the packaging to ensure they are suitable for whipping, and know that the frosting may not be as voluminous or stable.
- Is this marshmallow frosting safe for kids and pregnant people?
- Yes, when made as directed. Heating the egg whites and sugar to 160°F (71°C) over a double boiler is sufficient to kill any potential salmonella, making the frosting safe for all to enjoy.
- Can I toast marshmallow frosting?
- Absolutely! Use a kitchen torch to gently toast the peaks of the frosting for a golden, s’mores-like finish. Avoid using a broiler unless the dessert is heat-safe and you can monitor it closely to prevent burning.
- Why isn’t my frosting forming stiff peaks?
- This usually happens if there is grease or yolk in the bowl, or if the sugar didn’t dissolve completely. Ensure your bowl and whisk are spotless, and that you heat the egg whites and sugar until completely smooth before whipping.
- How long will marshmallow frosting hold its shape?
- When piped onto cupcakes or cakes, marshmallow frosting will hold its shape for several hours at cool room temperature. However, in humid or very warm conditions, it can start to weep or deflate, so it’s best served the same day.
- Can I use this frosting under fondant or for decorating layer cakes?
- Marshmallow frosting is very soft and does not crust or firm up like buttercream. It’s not ideal as a base under fondant or for intricate decorations that require structure. It works best as a topping or filling for cakes and cupcakes that will be served soon after assembly.