Adam has done many covers (and a few interiors) for DC Comics over the years, and these are two examples of his working on the World's Finest heroes in the 21st Century, with homages to two classic covers from the era of Julie Schwartz, who used the idea of creating a cover then building a story around it.
Superman #264 (June, 1973)
DC Comics Presents: Superman #1 (October, 2004)
Original cover by Nick Cardy, and the issue features the first appearance of Steve Lombard (Clark Kent's WGBS sportscaster nemesis).
Batman #183 (August, 1966)
DC Comics Presents: Batman #1 (September, 2004)
Original cover by Carmine Infantino and Joe Giella, and for the solution to that mystery, read here!