Get all your ingredients measured out and ready before you start
Place the caster sugar and water into a high sided non stick pan, and heat on a low-medium heat. You can stir the mixture a little if needed
When the sugar is dissolved (this takes about 5 minutes), and the mixture turns clearer and doesn't feel grainy, turn the heat up to medium-high so the mixture bubbles, and do not stir it at all
Keep a very close eye on the pan, it will eventually star to turn golden, don't take your eyes off it as it happens all of a sudden! For me this takes about 11 minutes, but all hobs and stove tops are different
Once it's all nicely golden, take off the heat and add the butter, whisk it in quickly
Then add the cream and whisk that in as you pour it
If you like, add the vanilla and/or salt
Pour into an airtight container, or a bowl, and leave to cool on the side, then put in the fridge to thicken up
Stored in the fridge, the caramel sauce will last for 2 weeks. You can also freeze it for up to 3 months
To drizzle the caramel onto ice cream, heat some of the caramel in a bowl in the microwave for 10-15 seconds to loosen it. Any caramel that you re-heat must be consumed or disposed of, do not put it back in the original container