In a heavy Duty medium saucepan add granulated sugar over medium heat. Stir constantly with a rubber spatula until sugar melts.
First you'll see sugar turning into clumps. Then eventually it will melt. Once sugar melts add cubes of butter. Whisk vigorously until sugar combines with butter. In case you notice sugar separating from butter then just take it off the heat and whisk vigorously until sugar combines with butter. This should take 3-5 minutes.
Slowly pour heavy cream and pure vanilla extract. Whisk continuously until combined. Once you've added your heavy cream allow it to boil for about a minute.
Finally, remove from heat and stir in salt. Allow it to cool down completely. Enjoy!