I have always used Mrs Beeton's Everyday Cookery book. This particular book, is well over 30 years old, but I love the recipies and all the retro kitchenware in the pictures.
I should point out now, that I always work in ounces. Grams just scare me. According to the internet, 1 oz = 28.3495 grams. I'm going to round that to 30 grams. Yes, i'm getting the calculator out.
Preheat oven to 180 degrees
4oz / 120 grams Butter or Margarine
4oz / 120 grams Castor Sugar
4oz / 120 grams Self Raising Flour
Cream fat & sugar very thoroughly. Add well-whisked eggs gradually, beating well between each addition. Stir flour lightly into the creamed fat and eggs. Mix to a soft dropping consistency, adding water/milk if necessary. Place mixture in a prepared 7-inch sandwich tin, and bake in a moderate oven.
I also throw a bit of vanilla essence in as well. Can never have too much of that :)