Queen Elizabeth II was well known for watching her diet and preferred simple dishes with lots of fruit and vegetables over rich sauces. Another royal who has become famed for leading an incredibly healthy lifestyle is The Princess of Wales . While Kate has previously shared her love of superfoods such as avocados and green smoothies, there is one naughty end-of-meal treat that is said to be a favourite of hers. The princess' love of this tasty British classic will certainly make her popular