This cake is a south side Chicago tradition. We used to live not too far from Webers bakery at Archer and Harlem. They had the cake but they didn't call it atomic cake. I don't remember what it was called now but it was/is fabulous. As I recall it was pricy so we only had it for extra special occasions. Plus you needed a crowd as it is a lot of cake.
When our priest retired the 1st time the retirement dinner committee sent someone nearly and hour and and half drive time to the city to get this cake for the dinner. The priest requested it but not a whole lot of other folks at the dinner knew what it was.
I will still occasionally make the long trek to the city for Webers strudel and butter crust buns. Sometimes a taste from childhood is all that will cure a craving!