Bring a large pot of water and your olive oil to boil and cook your shells according to the package directions.

While your pasta is boiling, mix together your spinach, egg, garlic powder, salt, black pepper, Italian herbs, and all 3 cheeses

When your pasta is done, drain and rinse with cool water to stop them from cooking

Add a few spoonfuls of your marinara sauce to the bottom of your pan so the shells will not stick to the pan

Begin stuffing your shells using a large tablespoon and lay them in the pan, with the opening facing up

Once you're shells are all stuffed and in the pan, cover them with the rest of your marinara sauce

Then sprinkle them with more mozzarella and parmesan cheese. (as much or as little as you'd like)

Cover your pan with either a lid or aluminum foil and bake at 350 for 30 minutes

After the 30 minutes, remove your cover and bake for another 15 minutes until the cheese is bubbly and melted

Enjoy!