There’s one part of a Batman: TAS I’m remembering, but I can’t recall which episode it’s from. It involved Joker talking to somebody, and the person he was talking to sad something about Batman’s secret identity and whether he wants to know who Batman is. And Joker says something like “What do you mean who he is? I know who he is! He’s Batman!”
Or am I misremembering? Because I’m fairly sure this happened.