What are they, anyway? Well, here’s how to make them. They sound like sweet prunes, which should be got after eating figgy pudding.

THE MOST KINDELY WAY TO PRESERVE PLUMS, CHERRIES, GOOSEBERIES, &c.
You must first purchase some reasonable quanity of their owne juyce, with a gentle heat upon embers, in pewter dishes. dividing the juice still as it commeth in the strewing: then boile each fruit in his own juyce, with a convenient proportion of the best refined sugar.

Recipe [GodeCookery.com via BoingBoing]