Received with thanks from Dean Lewis, lewis.associates@home.com:

This is E. Doreen Lewis' recipe for 'Heavy Cake'.  Her Cornish heritage 
goes back to Marazion's Hammill family. [Eva Doreen Lewis (nee Jenkin)]

HEAVY CAKE
2 cups flour,
4 tblsp. sugar,
5 oz. (about one-third lb.) butter and lard mixed,
salt,
1 cup mixed raisins and currants,
milk to mix.

Sift flour with a pinch of salt.  Rub in fat roughly. Mix in sugar and 
fruit.  Add milk to make a fairly soft dough. Roll out into an oval shape 
about three-quarters of an inch thick. Score the top both ways in a 
lattice pattern. Bake at 400 degrees for about 30 minutes. Cut into 
squares while hot.