1) The OED has a reference to ‘speysse-bred and wine’ in 1550 and the inference is that this was richly flavoured bread or cake which contained raisins, plums, figs or the like.
As a delicacy it actually has a much longer history and was being imported into Hull in the fifteenth century, from Danzig: 1453 1 bar’ spycebrede
1465 8 skok spysed brede. It was almost certainly being made in some of the monasteries from the late thirteenth century, for Selby Abbey allowed small quantities to certain privileged tenants as part of their ‘payment’: 1320 ‘and he shall carry half a skep of wheat at Christmas to Seleby and shall have a loaf of Lespeys bread’. Perhaps it was a seasonal delicacy.