Preheat the oven to 375°F (190°C) and lightly spray a 9x13-inch baking dish with nonstick spray.
In a large mixing bowl, combine the ricotta, 1 cup shredded mozzarella, grated Parmesan, large egg, garlic powder, and dried parsley until evenly mixed.
Spoon about 3 to 4 tablespoons of the cheese mixture onto the center of each egg roll wrapper and roll up tightly, tucking the sides as you go so the seam ends up on the bottom.
Spoon a thin layer of spaghetti sauce across the bottom of the prepared baking dish.
Place the rolled manicotti seam-side down in the dish in a single layer.
Pour the remaining spaghetti sauce over the rolls, then sprinkle the remaining 1 cup shredded mozzarella evenly on top.
Cover the dish with aluminum foil and bake for 20 to 25 minutes.
Remove the foil and bake an additional about 5 minutes, until the cheese is melted and lightly golden; remove and let rest a few minutes before serving.
