Preheat oven to 350 degrees F (175 degrees C).
Bring a large pot of lightly salted water to a boil. Add pasta and cook for 8 to 10 minutes or until al dente; drain.
In a large bowl, mix egg, ricotta, half the mozzarella, half the Parmesan, basil, salt and pepper until well combined.
Add half the sauce to the bottom of a 9×13 baking dish. Stuff cooked shells with ricotta mixture and place in the baking dish over the pasta sauce. (you should have 18-20 shells).
In a medium bowl, stir together pasta sauce and reserved mozzarella and Parmesan. Pour over stuffed shells.
Bake in a preheated oven for about 30 minutes, until edges are bubbly and shells are slightly set.