Before you begin: It may be helpful to watch the video above before beginning if you have never made a meringue buttercream before. Also, make sure all of your bowls and tools are clean, dry, and grease-free!

Set up your double boiler: You may use a double boiler, a medium-sized saucepan with a bowl that fits snugly in without touching the bottom or, my preference, a metal stand mixer bowl that fits snugly in a medium-sized saucepan without touching the bottom.

In the bowl of your double boiler, whisk together granulated sugar, egg whites (make sure there’s no yolk mixed in!) and salt until completely combined.

Fill a medium-sized saucepan with about 1 ½” of water and make sure your egg whites bowl rests in the saucepan without touching the water. Remove bowl, turn stovetop heat to medium, and bring water to a simmer.

Once simmering, place bowl on the saucepan and whisk the contents constantly until the sugar is dissolved and/or the mixture reaches at least 160F (71C). To test if the sugar is dissolved, take a small drop of the mixture and rub it between your fingers, it should feel smooth and not gritty.

Remove the bowl and wipe the bottom dry. If using a double boiler bowl, transfer to the bowl of a stand mixer, and if using a stand mixer bowl attach to your stand mixer now. Fit mixer with a whisk attachment and begin to beat the mixture on medium speed. Slowly increase speed to high and beat until meringue is thick and glossy and significantly increased in volume and you have reached stiff peaks (meaning the peak that forms when you lift the beater out of the mixture holds its shape and does not fold over or fall back in on itself). This will take approximately 8 minutes, meanwhile, melt your chocolate:

Place chopped chocolate in a microwave safe bowl and melt in 20-second intervals, stirring well in between, until chocolate is completely smooth and melted. Set aside.

Once your meringue has reached stiff peaks, switch the whisk attachment for a paddle attachment. Make sure the mixture is cooled to room temperature; the outside of the bowl should not feel warm anywhere you touch it.

Set mixer speed to medium and add butter, one Tablespoon at a time, not adding the next Tablespoon until the previous one is completely mixed into the meringue.

Once butter has all been added, check your chocolate temperature. It should still be smooth and melted but should not feel warm to the touch. Once it meets this criteria, slowly drizzle it into your buttercream with mixer on low-speed.

Stir in vanilla extract, scrape the sides and bottom of the bowl, and stir briefly to ensure everything is well incorporated.

Use as desired over cakes or cupcakes.