First tip the golden caster sugar into the saucepan, give it a little shake to level it out, place it over a medium heat and leave it just like that.
Keep an eye on it until the sugar begins to melt and turns into liquid all around the edges. This will take 4 to 6 minutes, and you need to just leave it be. Don’t be tempted to stir it. When it starts to melt all around the edges, give the pan a good shake, leave it on the heat until about a quarter of the sugar has melted.
Now using a wooden spoon stir it gently, until the sugar crystals have all transformed into liquid, and you can see there’s none left on the back of the spoon. Continue to cook, stirring now and then, until the melted sugar turns to the colour of dark runny honey. The whole thing should take from 10 -15 minutes.
Now take the pan off the heat, and add two tablespoons of warm tap water. Stand back as it may splutter a bit at this stage. Then put the pan on a gentle heat, and stir to melt any lumps that may form. Finally stir in the double cream, let it cool then transfer to a jug or lidded container and store in the fridge for up to two weeks.