This recipe comes from The Official Downton Abbey Cookbook which is quite similar to other gingerbread recipes of the era.
What is particularly enjoyable about this book is that is prefaced by the historical background which I also like to provide.
“Ginger was one of the cheapest spices in the past, so gingerbreads were very popular among the working classes. Nearly every European country had its own version, and in England, there are many regional types. In Yorkshire, where Downton Abbey is set, a type called Parkin (my recipe here), was made with rolled oats, was popular. However the staff at such houses would have expected slightly better food than the locals were eating, so this version uses only flour. This recipe is adapted from a handwritten book kept by Avis Crocombe, a Victorian cook who, like Mrs. Patmore, worked in a large country house. The cake is very practical for busy cooks, as it keeps for months, which means it can be made well in advance and stored when needed.” Annie Gray