Marble Cake (quick and easy)

Oven: 180 deg.C - 350deg.F - gas 4
Ingredients for small cake:
125g soft unsalted butter
125g sugar (Demerara or caster)
1/2 tsp. vanilla extract  (or 1/4 tsp. vanilla and 1/4 tsp. almond)
2 large eggs - beaten
125g self-raising flour (sifted)
pinch of salt
2-3 tablespoons of warm (previously boiled) water
(double the quantity for a larger cake)
Chocolate mix:
rounded tablespoon of cocoa powder (sieved) plus
approx. 1 tablespoon of milk or water

1. Cream the butter and sugar together, adding the vanilla extract.
2. Add the eggs with a tablespoon or so of the flour.  The flour should prevent the mixture from curdling.
3. Sift in the remaining flour and salt and gently beat together.
If the mixture seems a little stiff add some of the warm water. 
4. Mix the cocoa powder and water/milk together and swirl into the mixture.
5. Grease and flour your baking tin and place the mixture in. 
Level it off with a knife and tap the tin gently down to make sure there are no air bubbles.

6. Bake for approx. 30 - 45 mins - test with a skewer to see if cooked through.  (The skewer should come out clean without any cake mix sticking to it.)

Little tip: If the cake still looks uncooked in the centre - you can usually hear it !  Bake until it is just coming away from the sides of the tin - but test with a skewer anyway.

To serve - dust with icing sugar.