Preheat oven to 350 degrees.
Cook pasta according to package directions.
While pasta is cooking, prepare cheese mixture. In a large bowl, combine the ricotta cheese, 1 cup shredded cheese, egg, pepper, parsley, and Parmesan cheese.
When pasta is done cooking, drain and add into cheese mixture. Stir until pasta is coated and the cheese is melted.
Stir in sauce.
Add olive oil to a 12-inch iron skillet or an oven proof skillet and pour in the spaghetti mixture.
Cover and bake for 30 minutes.
Add remaining shredded cheese.
Leave dish uncovered and return to the oven. Bake until the cheese has melted, or about 10 minutes.