Preheat your oven to 375°F (190°C).

Bring a large pot of salted water to a boil. Add the jumbo pasta shells and cook according to package instructions until al dente. Drain and set aside.

In a skillet over medium heat, melt the butter. Add minced garlic and sauté for about 1 minute until fragrant.

Pour in the heavy cream and bring to a gentle simmer. Stir frequently for about 5 minutes.

Gradually whisk in the grated Parmesan cheese until melted and smooth. Season with salt and black pepper to taste. Remove from heat.

In a mixing bowl, combine the cooked chicken, ricotta cheese, half of the mozzarella cheese, Parmesan cheese, garlic powder, Italian seasoning, salt, and black pepper. Mix until well combined.

Spread a thin layer of Alfredo sauce on the bottom of a baking dish.

Using a spoon, carefully fill each cooked shell with the chicken mixture and place them in the baking dish, open side up.

Once all shells are filled, pour the remaining Alfredo sauce over the stuffed shells.

Sprinkle the remaining mozzarella cheese on top.

Cover the baking dish with aluminum foil and bake in the preheated oven for 20 minutes.

Remove the foil and bake for an additional 10 minutes, or until the cheese is bubbly and golden brown.

Remove from the oven and let it cool for a few minutes before serving. Garnish with chopped parsley.