Pre-heat oven to 170c. Grease an 8 inch round baking pan.

Weigh the 3 eggs( with the shells ).

Take the same weight of flour, caster sugar and margarine. E.g if the weight of the eggs is 200g, then weigh 200g of flour, caster sugar and margarine.

Seive flour + baking powder into a mixing bowl, add the sugar, margarine, vanilla. Crack the eggs and mix everything well until mixture is fluffy. You can add a little water (not more than 1/4 cup) to get the right consistency.

Bake for about 40-45 mins or until a toothpick inserted at the centre, comes out clean.