Measure out all of your ingredients into separate bowls (100g granulated sugar, 30g butter, 60ml single cream). Cut the butter into small cubes (this’ll help you to incorporate it into the sauce quickly).
Put the sugar into a large saucepan spread evenly across the bottom and place onto a medium heat.
Once the sugar has clearly started to melt, gently move the sugar about the pan with the spatula until it has all melted.
Once the sugar has melted continue to stir gently with the spatula until it has turned a light brown colour.
As soon as the caramel is light brown, carefully add the butter and whisk rapidly until the butter has melted and is combined.
Turn off the heat and add the cream, again whisking rapidly until combined.
If there are any small sugar crystals, pass the sauce through a metal sieve to remove them.
Put into a bowl or jug and refrigerate to cool.