Look for the first platform that isn't connected to the edges in any way - it's just hanging in space, and you have to jump under it and survive. I did it on my first try if I remember correctly, once I figured out what I was looking for.
I just went back and did it again... It's a little trickier than I remembered. You have to wait until you hit the peak of your first jump before you move under the spike and jump again. Unfortunately, I can't really show getting the 'quest' award since I already got it back when I was running through for the quests.
