Most marshmallow recipes start with gelatin packets and boiling-hot sugar syrup, but this marshmallow frosting is much easier. All you need to do is heat up sugar and egg whites until they’re just hot to the touch, then throw the mixture into the bowl of a stand mixer and whisk it into tall, billowy peaks. Try this fluffy vanilla-flavored topping sandwiched between chocolate graham crackers, or pile it on chocolate cupcakes and toast the peaks.
Game plan: To toast the marshmallow icing, you can use a small kitchen blowtorch. Alternatively, your cake or cupcakes can be toasted under the broiler.
8 large egg whites, at room temperature
2 cups granulated sugar
1/2 teaspoon cream of tartar
1/8 teaspoon fine salt
2 teaspoons vanilla extract
Fill a medium saucepan with 1 inch of water and bring it to a simmer over medium heat.
Place the egg whites, sugar, cream of tartar, and salt in the clean bowl of a stand mixer and whisk by hand to combine. Nest the bowl over the saucepan, making sure the bottom of the bowl is not touching the water. Heat the egg white mixture, whisking constantly, until the sugar has dissolved and the mixture is hot to the touch (about 120°F on an instant-read thermometer), about 6 minutes.
Transfer the bowl to a stand mixer fitted with the whisk attachment. Turn the mixer to medium and whisk for 1 minute. Increase the speed to high and whisk until stiff, glossy peaks form, about 5 minutes more. Add the vanilla and whisk until just incorporated, about 1 minute. Use immediately or store in an airtight container at room temperature for up to 3 hours.