The Queen cannot travel without this one snack

The Queen cannot go without her chocolate biscuit cake. Photo / Getty

It's well known that the Queen never leaves the house without her patent black Launer handbag, however, that isn't the only thing Her Majesty can't be without.

Former Royal Chef Darren McGrady, who cooked for the royal family for 15 years, has revealed that, much like the rest of us, the monarch is always careful to travel with a snack, reported the Daily Mail.

In an interview with Harpers Bazaar, McGrady revealed that the Queen always keeps her favourite chocolate biscuit cake close at hand.

Chocolate biscuit cake. Photo / Getty

In fact, the queen is so fond of the pudding she takes a supply with her while travelling - for example if she is going to Windsor the monarch will ask for a senior chef to accompany the dessert on the train journey up.

Speaking to the magazine McGrady said: "Now the chocolate biscuit cake is the only cake that goes back again and again and again everyday until it's all gone."

"She'll take a small slice every day until eventually there is only one tiny piece, but you have to send that up, she wants to finish the whole of that cake."

And it isn't just the Queen who is a fan of the chocolatey pudding, with both Prince William and Prince Harry also said to enjoy the snack.

Former chef to Prince Charles and Princess Diana Carolyn Robb revealed that she used to make the treat for the young princes.

Prince William is such a fan of the cake that he had it as his wedding to Kate. Photo / Getty

Speaking to You Magazine Robb said: "It was a firm favourite in the royal nursery; so much so that, many years later, Prince William chose to have chocolate biscuit cake at his wedding for the groom's cake."

"It was designed, made and gifted to Prince William by McVitie's biscuit manufacturers and is said to have been made from 1,700 biscuits and 17kg of chocolate."