LONDON, United Kingdom - For their wedding next month Britain's Prince William and Kate Middleton announced Sunday that they aren't just having their cake and eating it - they're having two.

The couple said they had decided on a "multi-tiered traditional fruit cake" with a floral design, followed by a chocolate biscuit cake that was one of William's childhood favourites.

The main cake, which will take centre stage at the Buckingham Palace reception on April 29, will be made by celebrity cakemaker Fiona Cairns who counts former Beatle Paul McCartney and rockers Pink Floyd among her clients.

Cairns said Middleton, 29, had played a key role in designing the cake.

"She has guided us right from the beginning and has quite strong ideas," said Cairns, who started her business at her kitchen table a quarter of a century ago in Leicestershire, central England.

"That makes it much easier than a bride who has absolutely no idea whatsoever, which has happened in the past. But she knew very much what she wanted and she brought us mood boards and told us what influences she would like us to use on the cake."

The cake will be decorated using cream and white icing with a "strong British floral theme" employing the Joseph Lambeth technique, a traditional English style that uses three-dimensional scrollwork.

It will contain dried fruits such as raisins and sultanas to walnuts, cherries, grated oranges and lemon, French brandy and free range eggs and flour.

The decorations will also feature William and Kate's new cipher, thought to feature the couple's entwined initials, which will be officially released on their wedding day.

But the second, less formal cake will have a special resonance for William - as well as appealing to chocoholics and those who find traditional wedding cake a little heavy.

The prince asked British biscuit maker McVitie's to create it according to a special recipe from the kitchens at Buckingham Palace.

"When Prince William was a young boy he would have it for tea and really enjoyed it," said Paul Courtney, the firm's cake design and development head chef.

"It has a couple of secret ingredients we can't tell you about but it will have dark chocolate, to give it a really nice flavour, and use rich tea biscuits that will be broken up."

McVitie's have made wedding cakes for the royals for decades, including for the diamond wedding anniversary of Queen Elizabeth II and Prince Philip in 2007.

William - the son of heir to the throne Prince Charles and the late Princess Diana - will marry Kate in London's historic Westminster Abbey. Key details, including the designer of her dress, are yet to be revealed.