Charles and Camilla surprise schoolchildren during Tower of London visit

The cake, symbolising the lantern used to guide the chief warder as he locks up the tower – once a prison and place of execution – each night, was gifted by Camilla and made by Julie Brownlee, who has previously baked for the duchess.

The cake included two small sugar figures of wardens dressed in the traditional ceremonial and everyday uniforms standing alongside the gold lantern and a set of silver keys.

Before lifting a replica of Henry VIII’s hunting dagger to slice into the white chocolate and raspberry-flavoured sponge, Camilla quipped: “It’s going to be off with their heads.”

Admiring the artistry of the cake, Charles said: “It seems an awful pity to make a mess of it.”