At last! I did something right!
Time: <1 hour
In New Zealand, we first learn about Shrewsbury biscuits from Griffin's as a treat of stiff jam squashed atwix two biscuit halves, and the jam is forced through a decorative hole—the kids love it! But these are not Shrewsbury biscuits to the rest of the world. True Shrewsbury biscuits have no jam, and are a single biscuit. They've been made in this manner since before 1561 in the Shropshire town of Shrewsbury, England, according to The Book of National Trust Recipes by Sarah Edington.
The recipe I have based this one on is from that book, from Attingham Park, Shropshire. It is done by weight.
Preheat oven to 190°C.
Cream the butter and sugar until the mixture is pale and puffy.
Add the egg and beat in well.
Fold the flour, currants, and spice together into the creamed stuff, and kneed it into a smooth ball.
Roll it out onto a floured surface, until it's about 5 mm thick. It may break apart as you flatten it, so just keep rejoining those sunderings.
Cut into biscuit shapes, you may use a cookiecutter, and set them on a lightly greased baking trays.
First bake them for 5 minutes, then take them out for sprinkling caster sugar on the tops.
Bake for 10 minutes more until they are pale brown.
Eat after they're cooled.
There are other variations. Take these instructions from The Compleat Cook of 1658:
To make Shrewsbury Cakes - Take two pound of floure dryed in the oven and weighed after it is dryed, then put to it one pound of butter that must be layd an hour or two in rose-water, so done poure the water from the butter, and put the butter to the flowre with the yolks and whites of five eggs, two races of ginger, and three quarters of a pound of sugar, a little salt, grate your spice, and it well be the better, knead all these together till you may rowle the past, then roule it forth with the top of a bowle, then prick them with a pin made of wood, or if you have a comb that hath not been used, that will do them quickly, and is best to that purpose, so bake them upon pye plates, but not too much in the oven, for the heat of the plates will dry them very much, after they come forth of the oven, you may cut them without the bowles of what bignesse or what fashion you please.