Easter egg half shells progress down a conveyor belt after being cooled at the Bournville Cadbury factory in Birmingham. See NTI story NTICHOC. Annually Bournville produces 47 million shell eggs and the British will consume around 90m (shell) Easter Eggs this season â around 50% of them will be Cadbury Eggs. Because the British are one of the largest consumers of Easter Eggs internationally, it is fair to say that Bournville is the Easter Egg Capital of the World. Cadbury made its first creme-filled egg way back in 1923 and its first Easter Egg (shell) in 1875.