• Preheat your oven to 375°F. Grease a 9-inch x 13-inch x 2-inch (or similar size) baking dish and set it aside.
• Set a large stockpot of water to boil on the stovetop. You can salt the water if you like.

Make the cheese filling

• In a medium-size mixing bowl, place the egg, and beat well.
• Add all 15 ounces of the ricotta cheese, 1 tablespoon of the Parmesan cheese, salt, and pepper, and whisk well to combine. If the ricotta cheese is cold, you may need to mix with a spoon rather than using a whisk.
• Add the chopped basil leaves and about 1/4 of the total grated mozzarella cheese (4 ounces) to the ricotta mixture, and mix to combine. Set the bowl aside.

Finish the sauce

• In a separate medium-size bowl, place the tomato sauce. Add 4 to 6 ounces of tomato paste, and whisk to combine well. Set the bowl aside.

Cook the pasta

• Place the dried pasta in the boiling water and boil, stirring occasionally to prevent it from sticking to the bottom of the pot.
• Boil the pasta for about 2 minutes less than whatever cooking time is recommended on the package. If there is a range of cooking time, boil for 2 minutes less than the low end of the range.
• Drain the cooked pasta, return it to the pot, and toss it with one quarter (about 7 ounces) of the total marinara sauce mixture. Set the pasta and sauce mixture aside.

Layer the baked ziti ingredients

• In the prepared casserole dish, place about one third of the remaining tomato sauce mixture (about 7 ounces) in a single layer and spread into an even layer.
• Top with an even layer of half of the pasta with sauce.
• Dollop about half of the ricotta cheese mixture evenly across the top, and spread it gently into an even layer.
• Drizzle about half of the remaining pasta sauce (7 ounces) evenly across the top of the ricotta mixture.
• Sprinkle about half of the remaining mozzarella cheese (4 ounces) and 1 tablespoon of Parmesan cheese evenly on top.
• Layer on top all the sauce that remains (7 ounces).
• Dollop the remaining half of the ricotta cheese mixture evenly across the top, and spread it gently into an even layer.
• Add the second half of the pasta with sauce mixture in an even layer on top of the ricotta mixture.
• End with the remaining mozzarella cheese (8 ounces) in a single layer, then sprinkle the remaining 2 tablespoons of grated Parmesan cheese on top.
• Bake in the preheated oven for 30 to 35 minutes or until the cheese on top is golden brown in spots.
• Remove the dish from the oven and run a thin silicone or nylon spatula or knife around the perimeter to unstick the edges.
• Let stand for 10 to 15 minutes before serving warm.