UE_LOGFMT(LogTemp, Log, "Printing three doubles: {0}, {1}, {2}", GetActorRotation().Pitch, GetActorRotation().Yaw, GetActorRotation().Roll);
Output Log:
LogTemp: Printing three doubles: 16.404666058434792, -8.4564431394870727, -46.881993375868063
more info can be found here: