Superman and Batman have switched identities or filled in for each other on a number of occasions, usually as a ploy to save the other from being caught out about their secret identity.
But a more recent, and more fun, instance is issue 37 of Batman Rebirth, amidst the Batman/Catwoman love story. The couple agree to a double date with Superman and Lois Lane, to the Gotham County Fair, only to find that it's Superhero Night.
Naturally, instead of dressing as their actual superhero identities, which would be too convincing and conspicuous, Lois puts on the Catwoman outfit, Selina talks her way in dressed as the non super-powered Lois Lane, while Bruce and Clark switch outifts too, with Clark insisting on keeping his glasses on over the Batman cowl.
It's a great issue, that highlights the pair's mutual admiration and understanding, while also showcasing their occasionally immature rivalry and pettiness.