Apple and Sultana Loaf

I've been making this cake since I was a child, in fact the original recipe came from the kid's TV show, Blue Peter, in the early 80s!  I've converted it to metric for ease, and added some caramel icing, the recipe for which you'll find here, but it's fine without, and is the perfect accompaniment to a cup of tea.

Equipment -
900g loaf tin, lined

Ingredients -  
225g self raising flour
115g unsalted butter, diced
115g caster sugar
2 large eggs, beaten
Zest and juice of 1/2 lemon
Pinch of salt
85g sultanas
3 eating apples, peeled and cored (I use Granny Smith)

Method-
1. Preheat oven to 170C, 350F, gas4
2. Sift flour into bowl and rub in butter until it looks like breadcrumbs.
3. Mix in sugar, eggs, lemon and salt.
4. Mix in apples and sultanas.
5. Put mixture in the loaf tin, leveling the top and cover the tin with foil.
6. Bake for 1 1/2 hours, removing the foil for the last 15 mins to allow the cake to become golden.
7. Cool for 10 mins in the tin, then transfer to a wire rack to allow to cool completely.
8. Ice if desired, I think caramel icing goes well with this, but maple icing or cinnamon  buttercream would be nice too.