Preheat the oven to 190C Gas Mark
5. Cream the butter and sugar
together in a bowl. Gradually work in the flour, using
enough beaten egg to make a stiff paste. Turn on to a floured surface and
knead well. Roll out to an oblong 6 in wide
and 1/4 in thick. Divide in half lengthwise, spread
one half with jam or lemon curd, keeping the edges clear. Place the other piece of dough on
top and pinch the edges to secure them. Brush with beaten egg and lightly
mark into fingers with a sharp knife. Bake for 30 minutes, until golden
brown. Carefully cut into fingers and
transfer to a wire rack to cool.
To make pinwheel biscuits, roll out the
dough but do not cut it in half. Spread jam or lemon curd over the
dough, then roll up the dough from one long side like a Swiss roll.
Chill the dough in the freezer for 30 minutes, then cut the roll into
slices. Place on a baking sheet and bake as above.