In a medium saucepan over medium-high heat, combine the sugar and water, stirring to combine.
Simmer until the syrup has turned a dark golden color, about 10-12 minutes. A candy thermometer isn't necessary, but it's helpful. For a thick but pourable sauce your candy thermometer should read about 230 degree F. For a little thinner sauce aim for 225 degrees F.
Once the caramel is ready, whisk in the warm cream and simmer for another couple of minutes. Remove from heat and whisk in the butter, vanilla extract and salt. Serve warm or keep stored in the refrigerator. To reheat it, simply heat it up briefly in the microwave.
* Want a salted caramel sauce? Simply increase the salt to 3/4 teaspoon. * This caramel sauce can be made in advance and stored in the fridge, covered tightly, for up to 2 weeks.