In a medium saucepan set over medium-low to medium heat, melt butter. Mix in brown sugar and stir for 2 minutes. Mix in heavy cream and stir for 2 more minutes. Remove pan from heat and stir in vanilla and salt until well incorporated.

Pour hot caramel sauce in a jar and allow to cool completely. The caramel sauce will be thin when it is done cooking, but it will thicken up nicely at room temperature, and even more so once chilled. Store in the refrigerator for up to a month.

Recommended applications of caramel sauce: as a dip for apples, drizzled over ice cream, apple pie, brownies, cheesecake, bread pudding, pancakes, waffles, sweet potatoes...or eaten straight out of the jar with a spoon.