Preheat oven to 400°F (200°C).
Whisk egg in a bowl. Add ricotta, salt, pepper, parsley; mix until creamy.
Spread ½ cup marinara in 9×13 baking dish. Layer 4 noodles, 1 cup ricotta, 1 cup mozzarella.
Add 4 more noodles, ½ cup sauce, and 1 cup Parmesan.
Add 4 noodles, rest of ricotta, 1 cup mozzarella.
Add final noodles, 1 cup sauce, rest of mozzarella and Parmesan.
Cover with foil; bake 30 min. Uncover and lower oven to 375°F; bake 15 min more.
Cool for 10–15 minutes. Slice and serve.
