Bring a large pot of salted water to a boil, then add your jumbo pasta shells. Cook them for 8–10 minutes, or until they are al dente. Drain and set aside.

In a mixing bowl, combine ricotta cheese, shredded mozzarella, grated Parmesan, and egg. Mix until creamy.

Heat olive oil in a skillet over medium heat. Add minced garlic and sauté for 30 seconds. Add spinach and cook for 2–3 minutes. Stir into the ricotta mixture.

Sprinkle in Italian seasoning, salt, and pepper to taste. Mix well.

Preheat your oven to 375°F (190°C). Spread a layer of marinara sauce in a baking dish. Fill each shell with 2 tablespoons of the filling. Place shells open side up in the dish and pour remaining marinara sauce over.

Cover with aluminum foil and bake for 20 minutes. Remove foil and bake for another 10 minutes, until cheese is melted and golden.

Allow to cool for a few minutes before serving. Garnish with fresh basil.