In a saucepan, combine sugar, corn syrup, and water.
Cook over medium heat, stirring until the sugar dissolves.
Raise the heat and let it boil without stirring until it reaches the hard ball stage (around 240°F).
While the syrup cooks, beat the egg whites in a mixing bowl until soft peaks form.
Once the syrup is ready, slowly pour it into the beaten egg whites while mixing continuously.
Add vanilla extract and salt to the mixture.
Continue beating until the mixture thickens and holds its shape.
Fold in any optional ingredients like nuts or food coloring.
Drop spoonfuls of the mixture onto wax paper.
Allow the candies to cool and set for at least 2 hours before serving.