Melt the sugar and butter in a heavy-based saucepan over medium–high heat, stirring gently from time to time.
Add the cream and salt, mix well and leave the sauce to simmer for another 4-5 minutes or until the mixture is silky smooth, has darkened in colour and has thickened.
Remove the pan from the heat and set aside to cool. Notes:
Be careful when adding the cream as it will cause the mixture to bubble furiously.
To turn this into a luxurious pouring sauce, just use extra cream and the sauce will be thinner.
If your sauce starts to crystallize a little as it sets, this could mean that it either cooked too quickly or too slowly - difficult to monitor without a sugar thermometer.
However it's easily fixed, just re-heat the sauce for a couple of minutes before serving and the crystals will melt back into the sauce and it will be silky smooth again.Recipe reprinted with permission of Sarah Graham.