Melt the sugar in a thick bottomed saucepan with high sides.
Swirl the saucepan to melt the sugar evenly.
Once the sugar has a deep brown color, remove from heat and add all of the butter. (It will foam up)
Stir until the butter has melted completely into the sugar.
Whisk in the cream (more foaming).
Whisk until you have a consistent sauce.
Stir in half of the salt.
Set it aside to completely cool the stir in the rest of the salt.
Pour into glass bottle(s)/jar(s) and store in the refrigerator for up to two weeks.