Prune, Apple and Armagnac Cake - Delia's - good recipe for Christmas

Oven: 180 C : 350 F : gas 4 
20cm. tin (8" - greased and lined
Ingredients:
Prunes:
350g (12 ozs.) ready-to-eat prunes (stoneless)
75g (3ozs.) caster sugar
150 ml water   
75 ml. port or Armagnac

Place ingredients, except Armagnac,  in a saucepan, bring to boil, then simmer gently for 15 mins. 
Drain, discard the liquid - place the prunes in a bowl, add the Armagnac/Port, cover and leave overnight.
Delia soaks her prunes, (although it's not necessary), so if doing this, soak prunes the night before baking the cake.

Streusel Topping:
75g self-raising flour
25g butter - room temp.  ... crumb these 2 ingredients, then add
75g demerara sugar
Add 1 dessertspoon of cold water - stir in until mixture is coarse and lumpy - set aside

50g whole un-toasted almonds - halved lengthways and finely shredded - leave to one side.

Cake:
75g (3ozs.) self-raising flour
1/2 tsp. baking powder
50g (2ozs.) soft butter
25g (1oz.) ground almonds
50g (2 ozs.) caster sugar
1 egg (medium or large)
2 tblspns. milk
50g (2ozs.) diced Bramley apple

1.  Sift flour add baking powder
2. Add the rest of the ingredients (except for the apple)
3. Beat until smooth.
4. Fold in the apple then spoon the mixture into the prepared tin.
5. Arrange the prunes over the mixture then fork the streusel topping over them, and finally sprinkle the almonds evenly over the surface.
6. Place cake in centre of oven and bake for approx. 1 hr.  Remove it from the oven and leave in the tin for at least 30 mins before turning it out.
7. Sift icing sugar over the top before serving.