1. 1. Prepare the Lasagna Noodles: If using regular lasagna noodles, cook them according to package directions until al dente. Drain them well and lay them flat on a clean surface or parchment paper to prevent sticking. If using oven-ready noodles, you can skip the boiling step.

2. 2. Mix the Filling: In a large bowl, combine the cooked shredded chicken, thawed and squeezed-dry spinach, ricotta cheese, egg, 1/2 cup Parmesan cheese, garlic powder, salt, and pepper. Mix everything thoroughly until well combined. This is your flavorful core for the roll-ups.

3. 3. Assemble the Roll-Ups: Spread about 1/2 cup of marinara sauce evenly on the bottom of a 9×13 inch baking dish. Lay out one cooked lasagna noodle. Spread about 1/4 to 1/3 cup of the chicken and spinach mixture evenly over the entire surface of the noodle.

4. 4. Roll Them Up: Starting from one short end, carefully roll up the noodle tightly. Place the rolled noodle seam-side down in the prepared baking dish. Repeat this process with the remaining noodles and filling, arranging them snugly in the dish.

5. 5. Sauce and Cheese: Pour the remaining marinara sauce evenly over the tops of the rolled-up noodles. Make sure each roll-up gets a good coating of sauce. Then, sprinkle the 1 cup of shredded mozzarella cheese generously over the sauce. You can also add a little extra Parmesan cheese at this stage if desired.

6. 6. Bake to Perfection: Cover the baking dish loosely with aluminum foil. Bake in a preheated oven at 375 F (190 C) for 20 minutes. Remove the foil and continue baking for another 5-10 minutes, or until the cheese is melted and bubbly and the roll-ups are heated through. Let them rest for a few minutes before serving.