In a medium saucepan over medium heat, add the cubed unsalted butter. Allow it to melt completely, stirring occasionally to ensure it doesn’t brown.
Once the butter is melted, add the packed brown sugar. Stir continuously until the mixture is fully combined and starts to bubble gently.
Gradually pour in the milk while continuing to stir. Keep stirring until the mixture is smooth and well combined. This should take about a minute.
Remove the saucepan from heat. Stir in the vanilla extract and kosher salt, tasting to adjust the saltiness according to your preference.
Let the caramel cool for a few minutes before transferring it to a heatproof container. It will thicken as it cools, becoming the perfect consistency for drizzling or dipping.
