- 4 tablespoons (2 ounces) unsalted butter
- 3/4 cup packed dark brown sugar
- 3/4 teaspoon fine sea salt
- 1/2 cup heavy cream
- 1/2 teaspoon vanilla
- 1 to 2 tablespoons dark liquor, optional
In a medium heavy saucepan or skillet over medium heat, melt the butter. Add the sugar, salt, and cream and stir with a rubber spatula until combined. Without stirring, let the mixture cook at a bubbling simmer for three minutes. Be careful not to boil too long, or you’ll end up with chewy butterscotch candies instead of a sauce.
Remove from heat and let cool slightly before stirring in the vanilla extract. Pour into a resalable container, preferably glass. Don’t scrape the sides of the pan into the container or you may end up with gritty pieces of undissolved sugar.
Serving and Storage: The sauce should be served warm. It can be stored in a jar, in the refrigerator, for up to two weeks. Reheat the butterscotch sauce in a saucepan over low heat.