Add 1/2 cup light corn syrup, 1/4 cup water, and 1/8 teaspoon table salt to a small saucepan. Pour 3/4 cup granulated sugar into the center of the pot, being careful not to get any on the sides. Stir together and bring to a boil over high heat. Continue to boil until the temperature reaches 240°F on an instant-read or candy thermometer.
Meanwhile, add 2 large egg whites and 1/4 teaspoon cream of tartar to the bowl of a stand mixer fitted with a whisk attachment. Begin to whip the eggs to a soft peak at medium speed.
When the syrup reaches 240°F, reduce the mixer speed to low and slowly drizzle in about 2 Tablespoons of the hot syrup to warm the egg white. Slowly drizzle in the rest of the syrup, then increase the speed of the mixer to medium-high. Whip until the mixer is stiff and glossy, about 7 minutes. Add 1 1/2 teaspoons vanilla and mix for 2 more minutes. Refrigerate in an airtight container for up to 2 weeks.