Grease a 1 litre pudding basin well with butter. Sift the flour into a mixing bowl. Add the sugar, suet, bicarbonate of soda, ginger, egg, golden syrup, vanilla extract and milk. Finely grate in the zest of the orange, then halve the orange and squeeze in the juice. Mix all the ingredients together. Pour some extra golden syrup into the pudding basin (about 5 tablespoons), then pour the mixture in on top of it. Cover the pudding with a pleated sheet of greaseproof paper and tie in place with string. Cook on the medium setting of your microwave (750W) for 12 minutes. Let it stand for 10 minutes before turning out. Delicious served with cream or custard.