First begin by making the caramel. Place half the sugar into a heavy based pan and heat it gently until it begins to melt. Then add the rest of the sugar and melt until all of the sugar turns to syrup.
Take care as it's really easy to burn the muscovado sugar at this stage.
Heat the cream in a separate pan to boiling and then take the sugar off the heat and add the cream, be careful as this will bubble up and lots of heat will escape.
Stir the caramel until it stops bubbling and then slowly add the salted butter a few cubes at a time and stir until it is melted and combined.
Pour the caramel into a bowl and allow to cool.
To make the ice cream, place the cream and the evaporated milk in a the bowl of a stand mixer and whisk until it is a thick cream and forms stiff peaks. This may take a while.
Then slowly whisk through the 100g of caramel, this will turn the cream a milky coffee colour.
When the caramel is mixed through take the ice cream mix and stir through some more of the caramel so that is it not completely mixed in and is more like a ripple.
Place the ice cream in a loaf tin or tupperware container and cover with a lid or cling film. Put the ice-cream in the freezer for 6 hours or overnight.
Then you'll have a delicious ice-cream ready to serve, you can always add more caramel or chopped walnuts to serve.