First melt the unsalted butter and then add in the ingredients in the order listed all the way down to (and including) the walnut pieces.
Mix well and bake in a greased baking tin at 180 C / Gas Mark 4 for 20 - 25 mins. Keep checking on them and pull them out when they are at the consistency you want. Don't forget that they will continue to cook for a while once you have got them out of the oven.
Heat the granulated sugar up slowly on a medium heat. Keep stirring it until it turns in to liquid. Be careful not to burn it.
Using a whisk add the butter to the pan and keep stirring until it is melted.
Add in the cream. Be warned that it could bubble up at this point. So add it slowly and continue stirring. Bring to the boil.
After a minute of boiling, remove from heat, add the salt and leave to stand.