Before you start, make sure that you have the butter, cream and salt measured out and placed close to where you are going to cook the sugar. This makes it much easier once you are making the caramel sauce.
Place the sugar into a medium sized saucepan and place over a medium heat. Allow the sugar to liquefy (this takes around 10 to 15 minutes depending on your stove top). During this process, you'll need to stir the sugar consistently to ensure it doesn't catch and burn. I use a whisk or spatula to do this. Be patient at this stage of the process!
Once the sugar has fully dissolved and is an amber color, remove from the heat and add the butter cubes. The sugar will froth up and seem like it's going to overflow - this is very normal. Whisk the butter continuously and vigorously until the mixture has completely emulsified together. It will look fairly thick and glossy at this stage.
Add the salt and continue to whisk.
Then slowly add the cream while continuing to whisk. You can stop whisking once all the cream has been added and the sauce looks rich and glossy.
Transfer the homemade caramel sauce to a clean jar and place into the fridge to thicken up.