Place your noodles in a single, slightly overlapping layer. I mean slightly—like a friendly handshake, not a bear hug. Overlap too much, and you’ll get doughy, raw spots in the middle.
And please, boil them al dente. They’ll keep cooking in the oven. Mushy noodles are the enemy of structure. (I know, I know, we all love comfort food, but mushy is not comfy.)