Lasagna noodles can either be cooked prior to layering in the lasagna or not. It also depends on the type of noodles used. For example, this recipe calls for Barilla oven-ready lasagna sheets that don't require boiling beforehand. If you plan on making your own fresh pasta, you also don't need to cook the pasta beforehand. Fresh pasta cooks much faster than dry pasta. However, if you use regular pasta noodles, you can either boil them beforehand or use them dry. So in most cases, you do not have to boil the pasta before layering it.