Knife-wielding Princess Anne has branded not eating cake “legalised vandalism” as she cut out slices during today’s engagement. The Princess Royal, who is known for her dry humour reminiscent of Prince Philip, visited Wormwood Scrubs Pony Centre in London today. Princess Anne, who is Vice Patron of the British Horse Society, was celebrating the pony club’s 35th anniversary. She was presented with a birthday cake to help celebrate the club’s anniversary, to which the princess said: “I hope you’ve all had a chance to see this cake because it really is stunning. “The instructions on it are you wi…