The hosts immediately started to pass the ball around neatly, but Nuremberg's defensive shape meant that they struggled for chances early on.
Indeed it was Nuremberg who came closest to breaking the deadlock in the opening 15 minutes as Daniel Ginczek rattled the crossbar with a fine strike from 30 yards.
It was Alaba and not Robben who stepped up but Schafer guessed right to dive and keep the penalty out.
Bayern piled on the pressure in the second half and following two top saves from Schafer they finally broke the deadlock in the 72nd minute as Franck Ribery headed in Philipp Lahm's fine cross.
With 10 minutes to go Bayern made the points secure with Robben doubling the lead with a fine solo effort finished with a powerful low strike.