Preheat the oven to 375°F (190°C).
Cook the manicotti pasta according to package instructions. Drain and set aside.
In a bowl, mix ricotta, 1/2 cup mozzarella, Parmesan, egg, garlic powder, Italian seasoning, salt, and black pepper.
Fill a piping bag or spoon the cheese mixture into the manicotti tubes.
Spread 1 cup of marinara sauce in a baking dish.
Arrange the filled manicotti in the dish and cover with the remaining sauce.
Sprinkle the remaining mozzarella cheese on top.
Cover with foil and bake for 30 minutes.
Remove foil and bake for another 10 minutes until the cheese is golden and bubbly.
Let it rest for 10 minutes before serving. Garnish with fresh basil.