Blackcurrant and lemon marble cake

Lu's nan is very ill in hospital at the moment. We're all feeling pretty helpless and all I can think to do is bake - Avril isn't eating much of the hospital food, but I hoped a slice of cake would tempt her, and can feed all her visitors! 

Ingredients

10 oz margarine

10 oz caster sugar

5 eggs

1 tsp lemon extract

10 oz self-raising flour

1 tsp baking powder

4 tbsp blackcurrant jam

For the filling

4 tbsp blackcurrant jam

For the icing

6 oz icing sugar

1 tbsp Ribena

1 tsp lemon extract

½ tsp pink food colouring

2 tbsp blackcurrant jam

2 oz margarine, softened

To decorate

Edible pink glitter sprinkles

Method

1. Preheat the oven to 170°C.  Grease and line two 9 inch round cake tins.
2. In a large mixing bowl cream the butter, sugar and lemon extract together until pale and fluffy.
3. In a separate bowl or jug, beat the eggs.
4. Add the eggs to the butter and sugar mixture a little at a time, beating well after each addition.
5. Sift in the flour and baking powder and beat until combined.
6. Spoon two thirds of the mixture into the prepared cake tins.
7. Add the blackcurrant jam to the remaining third of the cake batter, and mix well to combine.
8. Dollop teapoonfuls of the blackcurrant cake batter into the cake tins.  Use a skewer or knife to drag the blackcurrant cake mixture into swirls with the lemon cake mixture.
9. Bake for about 25-30 mins until springy when gently touched and a cake tester comes out clean.
10. Leave to cool in the tins for a minute or so before loosening them around the edges with a palette knife and turning them out on to a wire cooling rack to cool completely.
11. While the cakes are cooling, make the icing.  Sift the icing sugar into a large mixing bowl and add the Ribena, lemon extract and food colouring.  Beat together.
12. Add the softened margarine and beat well until thick.  (Add more icing sugar if necessary.)
13. Place the blackcurrant jam in a small saucepan and heat gently until runny.
14. Spread the jam over the inside of one of the cakes and then place the other cake on top.  
15. Use a palette knife to spread a quarter of the icing over the top and sides of cake to create a ‘crumb layer.’
16. Finish with a second layer of icing, smoothed with a palette knife over the top and sides of the cake. 
17. Decorate with pink glitter sprinkles.  Refrigerate until ready to serve.