There were two main types of recipes – those with Guiness and those without. I chose the latter. This recipe produces a cake rather than a biscuit and is baked in a 20cmx30cm tin or dish. It's moist and filling, a little like fruit cake, but much softer in texture, and with more 'warmth' at the back of the throat.
This is how it turned out in the pan. Since I took the gingerbread to school for taste testing and I'd just finished baking for market day, I didn't get any photos of it cut (darn). Pink Stripes blog has a some good pictures to give an indication of what the inside texture should be, when it's cut (and probably a heap more recipes to try).
Here's some other recipes I found while I was hunting (though I have to say I am really very pleased with the taste of this recipe and I think I might just have to make it again).
Irish Stout Gingerbread & Guiness Gingerbread & Nigella Gingerbread.
Google was my source for recipes so if you reading are Celtic or of Celtic origin and know the below better than me please feel free to correct me. Happy Celtic Gingerbread making!