Rum-Caramel Sauce

Why I Love This Recipe
This is a super yummy caramel sauce from Cook's Illustrated. I prefer to use Captain Morgan's Spiced Rum.
Ingredients You'll Need
1 C water
2 C granulated sugar
1 C heavy cream
pinch table salt
2 tablespoon unsalted butter cold
3 tablespoon dark rum
Directions
1. Pour 1 cup water into heavy-bottomed saucepan; add sugar to center of pot to keep granules from adhering to sides of pot.
Bring to boil over high heat, covered.
Uncover pot, insert candy thermometer, and continue to boil until syrup is thick and straw-colored, registering 300 degrees on candy thermometer, about 15 minutes.
2. Reduce heat to medium; continue to cook until sugar is deep amber, begins to smoke, and registers 350 degrees on candy thermometer, about 5 minutes longer.
Meanwhile, bring cream and salt to simmer in small, heavy-bottomed saucepan over high heat. (If cream reaches simmer before syrup reaches 350 degrees, remove cream from heat and set aside.)
3. Remove sugar syrup from heat.
Pour about one quarter of hot cream into sugar syrup; let bubbling subside.
Add remaining cream; let bubbling subside.
Whisk gently until smooth; whisk in butter and dark rum. Let cool until warm; serve. (Reheat in microwave or small saucepan over low heat if needed before use.)