In addition to their popular "Changemaker" gum, in the early 1940's Topps also sold a candy bar dubbed Opera, which was a chocolate covered marshmallow confection. The origin of the name is a little murky as there was a much older product with the same name that featured two flavored fondant fillings but whatever its beginnings it was one of the first Topps products.
In anticipation of World War 2 sugar quotas, Topps began buying smaller candy companies and, as the story goes, began shutting them down and keeping their upcoming alltoments. However, in 1943 Topps bought a company called Bennett-Hubbard in Chattanooga, Tennessee and decided to keep their plant running to make candy.
Here's a wrapper from what might be their first confection made in the Chattanooga
I nicked that scan from the awesome Candy Wrapper Archive by the way. I originally though the wrapper below came first but the black bar at the upper left would have been utilized by a later cutting technology I believe:
(Courtesy of Jeff Shepherd)
Topps closed the Chattanooga plant, which only made candy, in the early 1950's and the The Opera bar does not seem to have survived any much longer either. I have to say it looks like it might have been pretty tasty!