This receipt has been claimed to be Tudor, if so, it could be the case that sweet potato was originally used, as the 'white' or 'Virginia' potato only came into use in England much later. It is very similar to the receipt for Potato Cheescake from 1807, and the Potato Pie of 1672.
We're obliged to our correspondent Phil Atkinson, for finding the following receipt from; "Peggy Hutchinson... a farmer's wife, for twenty-five years ... did all the cooking and brewing in a busy farmhouse, seating from eight to ten persons daily, and her prowess conferred on her much local fame. In less than two years she had become the foremost "Household" woman journalist in the North- her weekly articles appearing in the newspapers of five counties."
Original Receipt from Peggy Hutchinson's 'Old English Cookery Book' (Foulsham & Co.) of 1935;BISHOP AUCKLAND CHEESE-CAKES
These were a bite that melted in the mouth and the recipe was rarely given away.
Ingredients:
6 ozs. thoroughly mashed potatoes
2 ozs. melted butter
4 ozs. fine sugar
4 ozs. currants
1 oz. finely grated lemon peel
1 egg
1/4 teaspoonful lemon essence
Pastry for tartlet linings
A little rum
Method:
Stir all the ingredients together one way until thoroughly mixed.
Line patty tins or small tins with pastry, then fill with the mixture and bake.
When cooked, put a few drops of rum into each tartlet.