Preheat the oven to 17OC Gas 3
Butter and line a 450g (1lb) loaf tin
Cream together the butter and sugar
Add the orange zest and vanilla extract
Add the eggs one at a time
Mix in the flour and the orange juice
Spoon into the loaf tin and sprinkle with a couple of tablespoons of sugar.
Bake for an hour or until a skewer comes out clean
Cool in the tin on a wire rack