Boil the shells in salted water until al dente. Drain and set aside on a tray to cool slightly.
In a large bowl, mix together the shredded chicken, crumbled bacon, ricotta, mozzarella, parmesan, egg, garlic powder, onion powder, salt, and pepper until well combined.
Preheat your oven to 375°F (190°C). Lightly grease a 9×13-inch baking dish.
Fill each shell with 1–2 tablespoons of the chicken-bacon-cheese mixture and arrange in the baking dish, seam side up.
Pour the alfredo sauce evenly over the stuffed shells. Sprinkle extra mozzarella on top for a cheesy finish.
Cover the dish with foil and bake for 20 minutes. Remove foil and bake for an additional 10 minutes, or until the cheese is bubbly and lightly browned.
Let cool for a few minutes before serving. Garnish with chopped parsley if desired.