Heat the marinara sauce in a saucepan over medium heat until it starts to bubble. Lower the heat and let it simmer, keeping it warm until you're ready to serve.

In the meantime, whisk together the egg and milk in a small bowl.

In a separate bowl, combine the bread crumbs and salt. Optionally, you could place breadcrumbs and salt into a gallon plastic bag.

Dip each ravioli into the egg and milk mixture, ensuring it's fully coated. Then, dredge the ravioli in the bread crumb mixture until evenly covered. If you used the plastic bag method in the previous step, just add the coated ravioli to the bag and gently shake to coat.

Pour about 2 inches of oil into a large, heavy pan and heat it until a small bit of breading dropped into the oil sizzles and browns. Fry the ravioli in batches, cooking each one until golden brown, about 1 minute per side. Remove and drain on paper towels.

Sprinkle the warm ravioli with a small amount of Parmesan cheese. Serve immediately with the hot marinara sauce on the side.