It was an old English custom to place a piece of fruit cake under the pillow with the belief that they would dream of the person they would marry.
Wedding cakes, traditionally dark fruitcakes, are served at wedding receptions following dinner. In some parts of England, the wedding cake is served at a wedding breakfast. The 'wedding breakfast' does not mean the meal would be held in the morning, but at a time following the ceremony on the same day. In the 19th century, it was the tradition in England for unmarried wedding guests to put a slice of the cake under their pillow at night in hopes of dreaming of the person they would marry.