A former royal chef, one Darren McGrady, has offered a pretty delightful reveal about the Queen’s predilections. McGrady, who worked for the royal family for 15 years, said in an interview with Recipes Plus that the Queen’s preferred snack is a chocolate biscuit cake and that, yes, she consumes one slice of the cake—made at her house in Buckingham Palace— every single day.

If she’s traveling, per McGrady, the Queen transports a “supply” with her, noting that she would have a senior chef “accompany the dessert on the train,” if she were, say, heading up to Windsor. (Imagine being on a train and turning to a stranger and casually asking, “So where are you heading?,” and getting the response, “Oh, just hand-delivering the Queen her favorite cake. You?”)

McGrady explained that the Queen is something of a completist when it comes to the food.

“Now the chocolate biscuit cake is the only cake that goes back again and again and again every day until it's all gone,” McGrady said. “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.”

According to McGrady, Prince William and Prince Harry also enjoy the cake.

That no one has figured out a way to procure the recipe and sell this cake to the general public is perhaps the most curious takeaway here.