Combine butter, brown sugar, evaporated milk & coarse sea salt in a medium saucepan & cook over medium heat- stirring frequently

Bring mixture to a boil & then reduce heat to a simmer. Simmer approx 5-7 minutes or until mixture starts to thicken - whisking constantly

Remove from heat & whisk in vanilla

Transfer to a glass jar with a tight lid

Allow to cool slightly before using

Store in refrigerator & heat prior to use