Preheat the oven to 375°F and spray a 9x13-inch baking dish with nonstick spray.
In a large mixing bowl, stir together the ricotta, 1 cup of the shredded mozzarella, grated Parmesan, egg, garlic powder, and dried parsley until evenly combined.
Spoon 3 to 4 tablespoons of the cheese filling onto the center of each egg roll wrapper and roll up tightly, sealing the edge so the seam is on the bottom.
Spread 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 and sprinkle the top with the remaining 1 cup shredded mozzarella.
Cover with aluminum foil and bake for 20 to 25 minutes, then uncover and bake about 5 more minutes until the cheese is melted and lightly golden.