Basic Sponge Recipe

Ingredients

For each pint of liquid that the cake tin will contain, include:

• 2oz (50g) Soft margarine
• 2oz (50g) Caster sugar
• 2oz (50g) Self-raising flour, sieved. (Actually, I always use plain flour and add baking powder to make it into self-raising)
• 1 Egg
• A splash of milk

Or, for cake tins I’ve got:

In order to make a chocolate sponge cake (which, of course, is the best kind :) replace some of the flour with sieved cocoa powder - I usually use about an ounce (25g) of cocoa.

Method

1. Grease and line the cake tin(s) with either greaseproof paper or baking parchment. Then grease the lining paper. I generally don't bother lining the sides of the tin these days - it's easy enough to run a knife round the sides after it's baked and it saves all the messing around lining the sides...
2. Put the oven on to warm up whilst you're preparing the mixture. Gas mark 3 (170°C / 325°F).
3. Cream the margarine and sugar together. This is easier if the margarine is at room temperature, rather than straight from the fridge.
4. Gradually add the flour, cocoa and eggs, making sure that the ingredients are blended to a uniform consistency. Traditionally, this is the stage where you fold the flour and eggs into the mix, and are instructed to ensure you incorporate as much air as possible into the mixture. Although I do use what's largely a folding action, I still use the wooden spoon I used in the previous step (rather than a knife) and find that it's more important to ensure the ingredients are all mixed together well. If you sieve the flour into the mix from a reasonable height, I doubt you'll have any problems with not getting enough air into it.
5. Add the splash of milk, and mix well. I'm not completely convinced that you need the milk - it may just be a superstition of mine, or merely my own personalization of the recipe - but I like a moist cake, and find that this helps. The amount I add depends on the consistency of the mixture at this point; sometimes it's as little as a teaspoon, and it's never more than a tablespoon or so. I suppose experience has taught me what sort of consistency I'm after, and so I can judge how much to add based on that, but I can't even begin to explain what that desired (by me, after all, your cakes will no doubt by subtly different) consistency is.
6. Transfer the mixture to the cake tin(s) and put into the oven.
7. Enjoy the remaining cake mixture from the bowl :-) (although you shouldn't if you're in one of the risk groups for eating raw egg! Shame.)

Baking times will vary, depending on how big the cake is. Do not open the oven in the first half hour of baking! An 8” cake will take around 45 minutes, and cakes made in my 10” square cake tin take about 1 hour 15 minutes. The cake is ready when a skewer slid into the centre of the cake comes out clean.

Once out of the oven, leave the cake in its tin for about five minutes to cool - during this time is will contract from the sides of the tin a little, making it easier to run a knife round the edges and remove from the tin onto a wire rack to cool properly.