Pre-heat the oven to 350°F and grease and flour two 8 inch sponge pans.
Cream the butter and sugar together in a mixing bowl.
Add the eggs, a little at a time, to the creamed mixture.
Beat well after each addition.
Then add the vanilla.
Sift the flour and fold it in.
The mixture should drop off the spoon: if it doesn't, add a little hot water.
Divide the batter between the two cake pans and bake for 20-25 minutes.
Leave them in the pans for 5 minutes before turning out on to a wire rack to finish cooling.