Pre-heat the oven to 375. Lightly mist a 9x13 baking dish with cooking spray and set aside.
In a mixing bowl, combine the egg, ricotta, ¼ cup of the mozzarella, basil, and parsley and stir until well mixed.
Place the chicken breasts on a cutting board. Sprinkle both sides of the breasts with salt, black pepper, and the Italian seasoning. Using a sharp knife, slice the breasts from the side (creating a top and bottom) almost all the way through. Open each breast at the slit. Divide the ricotta mixture evenly amongst the four breasts and spread across the surface of one side (leaving the other half empty to fold over the filling). When all four breasts are topped on one side, fold the empty half over the filling to make a stuffed breast.
Transfer each stuffed breast to a single layer in the prepared baking dish. Spoon the pasta sauce over the chicken and around the dish. Bake in the oven for 25 minutes. Remove from the oven and sprinkle the chicken with the remaining ½ cup of shredded mozzarella cheese. Return the dish to the oven and bake for an additional 10 minutes until the chicken is fully cooked. Don’t worry if some of the ricotta filling leaks out into the sauce, you can just heap it all on top when you serve it!