Preheat oven to 160°C fan / 180°C conventional. Grease and line two 8-inch round cake tins.
In a large mixing bowl, cream the margarine (or butter) and caster sugar until light and fluffy.
300 grams Margarine or unsalted butter, 300 grams Caster sugar
Beat in the eggs one at a time, mixing well after each addition.
3 large Eggs
Fold in the flour and milk until the mixture is smooth and combined.
300 grams Self-raising flour, 4 tablespoons Milk
Divide the mixture evenly between the tins. Bake for 40-45 minutes until the cakes are risen, golden and the sponge springs back when pressed in the middle.
Leave to cool for 15 minutes in the tin, then turn out onto a wire rack and cool completely.