Growing up in England I remember using a cake tin for things like rock
cakes and even mince tarts. THe major difference between those pans and
the ones available in the US were the fact that the openings were a sort
of hemi sphere.. more like a shallow depression than a full hemisphere
(a demi Hemi?) I remember one with 6 spaces and the other with 12. It
isn't an ebelskiver or other cast iron pan. It was made out of sheet
metal .. same type of thickness/weight as a NA muffin tin.

Can any UK list members/readers identify these pans or even a source?

Thanks & seasons greetings....