Same here. If you're going by the method I've tried, it's really hard.
I've tried, after reaching the final area where the Goal Ring is, I head up onto the rail that leads up to the 1Up and some runs I use Cream to try to jump over and fly across and try to continue from there but by the time I land, the platform starts to lower nad it's already too low for me to be able to fly up top to keep going, anyway. Another run or two, I've tried Amy and using Tornado Hammer to get acrosss but, again, no luck.
How do you think it could be done? You going about it the same way?