Start by preheating your oven to 350 F.
Next, grease a 9x3 spring cake pan with cooking spray, then set it aside. If you don't have a cake pan, you can also use a pie dish!
Bring a large pot of water to a boil, on the stove, and salt it generously. Once the water is boiling, add in your spaghetti and cook it for 3 to 4 minutes less than the package recommends, so that it is very al dente.
Once the pasta is cooked, drain the water from it and set it aside.
Next, in a large bowl, whisk together the eggs, ricotta cheese, Italian seasoning, 1 cup of the Parmigiano Reggiano, sea salt, black pepper, and marinara sauce until they're fully combined.
Then, add your cooked spaghetti to the bowl and toss until the noodles are evenly coated in the sauce mixture.
Finally, transfer your spaghetti to the prepared pan and top with the shredded mozzarella cheese and the remaining Parmigiano Reggiano.
Bake your pie for 27-30 minutes, or until it is golden brown.
Once it's done, let it rest for a few minutes, then slice it into wedges.
Top each wedge with more marinara sauce, if desired, serve, and enjoy! Store any leftovers in the fridge for up to one week, or the freezer for up to one month.