Preheat oven to 425 degrees F. Lightly grease a casserole dish with cooking spray (I used a standard 9x13 inch dish but a round oven-safe skillet would also work well!).

Cook the pasta according to package directions so that it’s al dente. You want the pasta to be just slightly under cooked since it will cook more in the oven. Once cooked, drain and rinse with cold water to cool down. Toss lightly with olive oil to keep the pasta from sticking.

Meanwhile, prepare the filling. Steam the spinach for 1 minute until it’s wilted. Remove from the heat and place in a large bowl.

To the bowl with the spinach, mix in the ricotta, pecorino/ parmesan, garlic powder, Italian seasoning, egg, red pepper flakes, salt and pepper. 

Pour 1 cup of marinara in the casserole dish so that it fully covers the bottom. Fill each of the shells with about 2 tablespoons of the ricotta mixture and place them evenly in the dish. Repeat until all of the ricotta mixture is used up.

Spoon the remaining marinara sauce on top of the shells. Place the slices of mozzarella evenly around the top of the shells.

Bake in the oven for 20-25 minutes until the cheese on top is fully melted and bubbly. Serve with fresh herbs and ENJOY!