Blackout cake

Blackout cake, sometimes called Brooklyn Blackout cake, is a chocolate cake filled with chocolate pudding and topped with chocolate cake crumbs. It was invented during World War II by a Brooklyn bakery chain named Ebinger's, in recognition of the mandatory blackouts to protect the Brooklyn Navy Yard. After the war, the name persisted for a very dark chocolate cake and became common across the American Midwest. Ebinger's variety was very popular and became a signature offering, popular with Brooklyn residents, until the chain of more than fifty locations closed in 1972.

Source: Wikipedia