It is not an easy TL to write, but it is possible with a series. You needed.
1) CP win. The POD below are enough.
2) Italy not to enter war. This alone will stop A-H from collapsing in the war in most TL. This one is absolutely mandatory.
3) Cancel Gallipoli. Germany will be strained greatly by the extra UK army in France in 1915. Helps but not mandatory
4) A-H needs to get the third crown in Poland. Hard POD, but probably doable. Mandatory
5) A-H has to handle the impending Dual Monarchy renewal crisis. Mandatory.
6) Russia runs War Plan Germany, not War Plan A-H. This saves the Great Galicia crisis of 1914. Maybe A-H can get a chunk of the Ukraine/Belarus. Not Mandatory.
With all of this, you get a A-H roughly the population of Germany, so it could be seen as stronger, remember if Germany carries the bulk of the fighting, Germany will have much higher % of population killed than OTL and A-H less. The down side is A-H will be horribly hard to run. It is as close as i can get.
Now if you want just a much more powerful A-H than before the war, you need to fix the Dual Monarchy renewal crisis and keep Italy out of the war. You can read my TL for how I see Italy staying out of the war helps A-H. Over 90% of the improvement in the A-H is simply Italy not entering the war.
Or you could look at Wiking's "Conrad Turns East" as another base, and combine with something similar to what I see with Italy not entering the war. It will get you closer to what you want than my TL, because I am buffing the German performance through a better Navy. You end up with an A-H in great shape, if and only if, it resolves the Dual Monarchy renewal crisis. I can see this TL as plausible. I think A-H getting both the Dual Monarchy Crisis resolved and Poland joining A-H is a bridge too far for a realistic TL.