Combine water, sugar, and salt in a medium (3qt) saucepan over medium heat. Stir until syrup comes to a boil.
Let syrup simmer until honey-colored (6-8 minutes), shaking and swirling the pot as necessary for even caramelization.
Continue cooking the syrup until a light to medium amber, another minute or two.
Reduce heat to medium-low and immediately add heavy cream, stirring constantly. Continue to cook until temperature reaches at least 225° F. For a thicker sauce, cook to a higher temperature, but remove before soft ball stage.
Remove pot from heat and stir in vanilla. Transfer caramel to a heat-safe dish to cool.
~ Caramel will be runny when hot, and thicken when cool.
Recipe by Simple Sweet Recipes at https://simplesweetrecipes.com/homemade-caramel-sauce/