To a large stainless steel pan, evenly spread the sugar to the bottom of a pan. Heat the sugar over medium heat and begin whisking until sugar melts down. The sugar will become a lump, its perfectly normal in the process. Continuous whisking will ensure the sugar melts down. Continue cooking until a deep amber color is achieved or the thermometer reads 300F.

Add softened cubes of butter to this melted sugar.The mixture will rapidly bubble up when the butter is added. This is happening as very hot mixture is coming in contact with a slightly cold ingredient. Whisk the mixture well ensuring there are no lumps.

Take the pan away from heat, stir in vanilla extract and slowly drizzle double cream. Whisk well until you have a smooth sauce. Remember to be careful as the salted caramel sauce will rapidly bubble up. Add sea salt and whisk to mix well.

Allow the Salted Caramel Sauce to cool down and then carefully pour into the glass jars. I have stashed them away for 4 weeks too and still perfect.