The trusty sponge recipie that I use as the basis of 99% of my cakes. Add whatever, but you will always need these....
The oven at: 190c
2 eggs
100g self-raising flour - sift if you can find a sieve
100g caster sugar (but there's nothing wrong with granulated)
100g margerine (thats 10-11 of those mini flora portions, thank you college catering!)
Ideally, cream the marg & sugar before adding flour through a sieve, fold in then fold in the eggs, cracked and beaten. If you don't have the time, shove them together, but expect perhaps a flatter cake, you might want to increase the ingredients. Using the right ratio still, of course.
Now it can get a bit more creative....