To a medium saucepan, add all ingredients, except for the whiskey; over medium heat.
Turn the heat up to high and bring the caramel to a boil. Once it is boiling, turn the heat down to medium-high and gently boil for 3 more minutes.
Remove the pot from the heat and add the whiskey, stirring constantly, as the liquor will cause the caramel to bubble back up. Pour into one large mason jar, or individual jars, if gifting this sauce. Store in the refrigerator for up to 2 weeks.