White and Havertz scored braces to batter their London rivals 5-0
Mueller gave Bayern the lead in the 34th minute with a strike from outside the area which deflected off Barca defender Eric Garcia to confound keeper Marc-Andre ter Stegen.
Lewandowski struck the German champions' second in the 54th, tapping into the net from close range on the rebound after Jamal Musiala had hit the post as Bayern made a rampant start following the interval, hemming their hosts into their own half.
The Polish striker twisted the knife further into Barca by scoring again in the 85th, collecting the ball in the area after another shot had come off the post and tormenting the defence before calmly beating Ter Stegen.