The cake, which is presented in a specially commissioned cream and gilt commemorative tin, was given to guests of the British royal nuptials as a keepsake six years ago.
It has since found itself in the plush rooms of the Chiswick auction house in London, instead of crushed up at the bottom of the biscuit tin like so many fruit slices before it.
The sweethas the guideline price of £800 to £1000, however a similar slice went for £6,000 in 2014, meaning there are certainly a market out there with an expensive tooth.
Of course this isn't just any wedding cake.
The eight-tier fruit cake, which was the focal point of the wedding reception in 2011, was made by Fiona Cairns and took over five weeks to complete.
The sweet was embellished with 17 different types of foliage using the highly regarded Lambeth Method of 3D rows of intricately piped leaves and was finished with 900 exquisite sugar-paste flowers.
"With best wishes from TRH The Prince of Wales and The Duchess of Cornwall in celebration of the wedding of TRH The Duke and Duchess of Cambridge" are the words written on the accompanying card, which features a British Royal Crest in gilt.
The piece will go under the hammer as part of the Printed Books and Manuscripts auction taking place on 27 September.