Iced Gems. Loved these when I was a kid! I used to bite off the icing & put the cookie part back in the jar. Needless to say, when my mom/grandmother took the jar out to serve to guests they were not to happy to find a jar full of un-iced cookies.
Heinz Farley's Rusks - you felt very lucky as a child if your mum would buy a box and let you have one! I think there's something about them that appeals to children and adults of all ages, not just infants.