Instructions:
- Preheat oven to 375°F (190°C). Spread a thin, even layer of marinara sauce (about 1 cup) across the bottom of a 9x13 inch baking dish.
- Cook the jumbo shells in heavily salted boiling water according to package directions, reducing the cooking time by 2 minutes (cook al dente). Drain immediately, rinse with cold water to stop cooking, and lay them out on a baking sheet to cool slightly.
- Make the filling: In a large mixing bowl, combine the ricotta, 1 cup of the mozzarella, Parmesan, beaten egg, parsley, garlic powder, oregano, salt, and pepper. Mix thoroughly until uniformly combined.
- Stuff the shells: Carefully fill each cooked shell cavity with a generous amount of the cheese mixture.
- Assemble the bake: Arrange the stuffed shells neatly in a single layer over the sauce in the prepared baking dish, nestling them close together.
- Sauce and Top: Pour the remaining marinara sauce evenly over the stuffed shells, ensuring most of the pasta is covered. Sprinkle the reserved ½ cup of mozzarella over the top.
- Bake covered: Cover the dish tightly with aluminium foil and bake for 20 minutes.
- Brown the top: Remove the foil and bake for an additional 5 minutes, or until the cheese is bubbly and golden brown.
- Rest and Serve: Let the dish rest for 5–10 minutes before serving to allow the shells to set.