Great British Bake Off final to draw huge TV audience

It is possibly TV's most unlikely hit, but on Wednesday night, the final of the Great British Bake Off looks set to draw the biggest TV audience of the year.

Almost 11 million people tuned in last week for the semi-final, and even more are expected to watch tonight as the last three fight it out to be crowned the winner.

So how did a programme about puff pastry, meringue and chocolate become such a sensation?

David Sillito reports.