A Soul cake, a soul cake
A celebration of All Souls (2 November). The story goes that poor christians would offer prayers for the dead in exchange for food from the wealthy. More likely, they were baked as offerings for the dead in pre-christian times and it is another example of existing traditions being absorbed into christian culture.
Children will sometimes go visiting (like carol singing) chanting the rhyme above in expectation of Soul Cakes (by begging). The lines above seem fairly constant across versions but there is a middle part which varies considerably in length and content.
A Soul Cake is a hot cross bun without currants or a cross.