Melt together the butter, sugar, golden syrup, lemon juice and zest.
Pour into a large mixing bowl and allow to cool.
Whisk in the eggs and vanilla.
Sift together the dry ingredients then whisk into the lemon mixture, alternating with the milk, until you have a smooth batter.
Grease an oven-proof dish (the dish I used was approximatley 25cmx15cm and 10cm deep) then pour the batter into the dish.
Transfer to the oven and bake for 30-40 minutes or until a skewer inserted comes out clean.
In a small saucepan, melt the sugar, syrup, butter, lemon juice and zest together. Once the pudding comes out of the oven pour the syrup over and allow to absorb for 10 minutes before serving.