Salted Caramel Sauce

Steps

1. 1
   Warm the cream in a small pan until hot but not boiling, and cut the butter into cubes. Cold cream hitting hot caramel makes it seize into lumps and spit.
2. 2
   Spread the sugar in an even layer in a heavy, light-bottomed pan over medium heat. Leave it until the edges melt, then stir gently with a heatproof spatula — the lumps will melt.
3. 3
   Cook for 6–8 minutes until the caramel is clear and deep amber, like an old copper coin — about 175–180°C. Take it off a few seconds early, as it keeps darkening. Pale caramel tastes only sweet; dark brown caramel tastes bitter.
4. 4
   Off the heat, add the butter — it will foam violently — and whisk until melted.
5. 5
   Pour in the hot cream in a slow stream, whisking, then return to low heat for 1 minute to dissolve any lumps.
6. 6
   Stir in the salt and leave to cool; the sauce thickens as it cools. Keep it in the fridge for up to 2 weeks and warm gently before using.