Preheat your oven to 180°C (160°C fan). Grease and line a standard loaf tin with parchment paper.
In a large mixing bowl, cream together the softened butter and caster sugar until light and fluffy.
Beat in the eggs one at a time, then stir in the vanilla extract.
Gently fold in the self-raising flour, being careful not to overmix. Add the milk to loosen the batter.
Pour the batter into the prepared loaf tin and bake for 45-50 minutes, or until a skewer inserted into the centre comes out clean.
Allow the loaf to cool in the tin for 10 minutes before transferring it to a wire rack to cool completely.