The Birmingham-based chocolate maker said the limited edition bars would go on sale later this year.
The 126-year-old chocolate bar is described by auctioneers as "very rare, if unappetising".
Actor Garon Michael explains how he landed the role.
The museum is shutting temporarily so volunteers can clean and carry out minor fixes and repairs.
The plaque will be unveiled to women's and children's campaigner Elizabeth Cadbury on Thursday.
Cadbury Chocolatiers spend two days crafting the giant Easter treat - just don't drop it on your foot.
The British chocolate maker says it is disappointed to be stripped of the endorsement.
A deal between Mondelez and Hershey could create a food giant with sales of almost $50bn a year.
William Alexander Harvey is to be honoured after his work designing houses and community buildings.
