Mix sugar, corn syrup, and water together in a microwave-safe bowl.

Cook sugar mixture in the microwave until mixture is 250 degrees F (120 degrees C), or until a small amount of sugar mixture dropped into cold water forms a rigid ball, about 180 seconds.

Beat egg whites in a glass or metal bowl until stiff peaks form. Lift your beater or whisk straight up: the egg whites will form sharp peaks.

Stir sugar mixture into egg whites until no longer glossy, about 420 seconds. Stir in vanilla extract.