Wiktionary
potato cake
n. (Scotland and England) A savoury flat cake made from flour and mashed potatoes, often fried or baked.
Wikipedia
Potato cake
Potato cake is a term that is sometimes applied to various different food preparations using potatoes.
Usage examples of "potato cake".
In any case -- this much is certain -- his mother found some wrapping paper and packed up two little pieces of potato cake for me as I was taking my leave.