Preheat the oven to 400ºF and spray a 9x13-inch casserole dish with nonstick cooking spray.
Combine the parmesan, ricotta, and Italian seasoning in a bowl and set aside
Pour 1 cup of the marinara sauce onto the bottom of the baking dish.Then, place half of the bag of ravioli on top of the sauce so they are laying completely flat.
Spoon half of the ricotta mixture on top of the raviolis and spread it so they are mostly covered.
Then pour in 1 cup of the marinara sauce and spread it out on top of the ricotta mixture.
Sprinkle on 1 cup of the shredded mozzarella.
Repeat until all ingredients are used.
Bake lasagna uncovered at 400ºF for around 45 minutes.
Once the lasagna is done take it out of the oven and let it rest for 5 minutes.