Step 1

Preheat the oven to 375°F. Coat a 9x13-inch baking dish with cooking spray.

Step 2

Bring 3 quarts of water to a boil in a large pot over medium-high heat. Generously season with salt and add the pasta shells. Return to a boil. Boil, uncovered until tender, about 12 minutes. Drain well.

Step 3

While the pasta is cooking, in a medium bowl, combine the ricotta, 2 cups mozzarella, ½ cup Parmesan, 2 tablespoons parsley, Italian seasoning, salt, pepper, and egg. Stir until well blended.

Step 4

Spread 2 cups of marinara in the bottom of the prepared baking dish. Fill the shells with the ricotta mixture and place on top of the marinara in the baking dish. Spoon the remaining 1 cup marinara sauce over the shells. Sprinkle with the remaining 1 cup mozzarella and ¼ cup Parmesan. Loosely cover with foil.

Step 5

Bake for 20 minutes. Uncover, and bake for an additional 15 minutes or until the begins to brown. Garnish with the remaining 2 tablespoons of parsley before serving.