With any POD after the beginning of WWI, put the Habsburgs on the throne of Germany.
Perhaps in a scenario where Hitler is overthrown and the monarchy restored after the Anschluss and the former Allies are incredibly against a Hohenzollern restoration for some reason?That's pretty hard to achieve because if the Germans decided to reinstate the monarchy they would obviously go with the Hohenzollers. And if they should for whatever reason decide not to make the Hohenzollers Kaiser again, they would probably go with the Kings of Bavaria, Wurtemberg or Saxony.
Kaiser Ralph?After a short WWI with a CP victory, wait a generation and then have a marriage between a Hohenzollern princess and a Hapsburg prince, both low in the line of succession. Everyone senior dies in a series of disasters over a very short period, leading to the Hapsburgs becoming the German Kaiser.