Fill a small to medium saucepan with about 1–2 inches of water and bring it to a gentle simmer. Choose a heatproof metal or glass bowl that will sit on the saucepan without the bottom touching the water.

In that heatproof bowl, combine 1 ½ cups sugar, 1 tablespoon light corn syrup, 1/8 teaspoon salt, 1/3 cup water, and 2 egg whites. Whisk briefly to blend the ingredients.

Set the bowl over the simmering water (bottom of the bowl should not touch the water). Whisk constantly until the sugar is fully dissolved and the mixture is hot to the touch — you should not feel any grittiness if you rub a little between your fingers. This pasteurizes the egg whites.

Remove the bowl from the saucepan. Using a handheld electric mixer, beat the mixture on medium-high to high speed until it becomes voluminous, glossy, and holds soft peaks, about 5–7 minutes.

Beat in 2 teaspoons clear vanilla extract and continue mixing for about 1 more minute until fully incorporated.

Use immediately to frost or pipe onto cake or cupcakes as desired.