• The day before you want to churn your ice cream, place the bowl of your ice cream maker into the freezer.

For the salted caramel sauce:

• Put the sugar into a large, heavy-bottomed saucepan. Cook over medium heat, swirling the pan every now and then, until sugar has just melted and is a deep, golden colour (see Note 1).
• Remove the saucepan from the heat and add the butter. Whisk vigorously until butter is melted and fully incorporated, then return to the heat.
• Add cream to the pan in a slow, steady stream, while whisking constantly. Once all cream is incorporated, stop whisking and allow to bubble, undisturbed, for 1 minute.
• Remove caramel sauce from the heat and stir in the salt. Allow caramel to cool slightly, then transfer 2 tbsp of the sauce to a heatproof container, cover and place in the fridge for later. Keep rest to use in ice cream base.

For the ice cream:

• Place the double cream, milk and remaining caramel sauce into a medium saucepan. Place over low heat, stirring frequently, until caramel has melted into milk/cream and the whole mixture reaches just below a boil.
• While the cream mixture is heating, place the sugar and egg yolks into a large, heatproof bowl. Using an electric whisk, beat until the mixture is thick, pale and fluffy (the 'ribbon' stage).
• When the cream mixture has reached just below a boil, with the mixer on, add it in a steady stream to the egg mixture. Mix until incorporated, then pour through a heatproof, fine mesh sieve back into the saucepan.
• Return the saucepan to a medium-low heat. Stir the custard with a heatproof spatula as it heats up, until it becomes thick and glossy- about 8-10 minutes. Pour the custard into a heatproof container, cover the surface with clingfilm and allow to cool to room temperature before placing into the fridge to chill for at least 3 hours, preferably overnight.
• When the custard is thoroughly cold, churn it according to your ice cream maker's instructions. Using the KitchenAid attachment, this takes around 15-20 minutes.
• While the ice cream is churning, gently heat the reserved caramel sauce. I did this in the microwave (about 1 minute on the lowest setting), but you can do it in a saucepan if you prefer. Stir the sauce well to ensure it is smooth and evenly melted.
• When your ice cream has finished churning, transfer it to a freezer-proof container. Smooth out the ice cream, then drizzle the warmed caramel sauce evenly over the top. Place into the freezer to firm up for at least 3 hours before consuming. The ice cream will keep in the freezer for 3 months.