As the title says, the challenge is to make the Ottomans the dominant power of the European continent. Could you do this by having the Ottomans take Vienna in 1529 and later expand into Italy, Poland, the Ukraine, and southern Germany?
Assuming that the Ottomans were able to conquer and hold, say, Austria Bohemia, Milan and Venice, then the Hapsburgs are pretty much broken.
But with a POD that far back, the Ottoman Beylik may not even emerge, never mind develop the effective military machine that it did OTL.It's a possibility if Khan Ogedei didn't die and mongols continued after Legnica and Mohi. They would crush everything on there way, and the Turks would find it easy to conquer europe
Assuming that the Ottomans were able to conquer and hold, say, Austria Bohemia, Milan and Venice, then the Hapsburgs are pretty much broken.