"Have some Madeira, m'dear ..."
Well, unfortunately, there was none in the cupboard, but I used Muscat instead. No stout on hand either, so I just used Boag's beer, and instead of brown sugar, molasses and the butter I put in the equivalent weight of my unset fudge.
Apart from those changes for the sake of convenience, I stuck to the recipe.
Oh - perhaps not. It said "flour" and I used SR flour, so I may not need to rest the dough for the full twelve hours indicated.
The mixture smell is very appealing.
Bbl.