Creating Stuffed Creamy Tomato Basil Pasta Shells can be straightforward if you follow these simple steps:

1. Preheat Oven: Preheat your oven to 375°F (190°C).
2. Cook Pasta: Boil the pasta shells according to package instructions until al dente. Drain and set aside.
3. Prepare Filling: In a large bowl, combine ricotta cheese, shredded mozzarella, grated Parmesan, egg, chopped basil, garlic powder, salt, and pepper. Mix until well combined.
4. Fill Shells: Gently stuff each pasta shell with the cheese mixture using a spoon or piping bag.
5. Prepare Sauce: In a saucepan, heat the marinara sauce over medium heat. Stir in the heavy cream and olive oil until combined and warmed through.
6. Layer Sauce: Spread a thin layer of the creamy marinara sauce on the bottom of a baking dish.
7. Arrange Shells: Place the stuffed shells in the baking dish, open side up.
8. Top with Sauce: Pour the remaining creamy marinara sauce over the stuffed shells.
9. Bake: Cover the dish with aluminum foil and bake for 20 minutes. Remove the foil and bake for an additional 10-15 minutes until bubbly and golden.
10. Cool: Remove from the oven and let it cool for 15-20 minutes before serving.
11. Garnish: If desired, garnish with fresh basil leaves for added flavor and presentation.

These steps will guide you in creating this incredible dish effortlessly. The combination of creamy filling and rich sauce will make it a highlight at any meal!