Preheat your oven to 375°F (190°C).

In a large pot, bring salted water to a boil. Cook the lasagna noodles according to the package instructions.

In a mixing bowl, combine shredded chicken, ricotta cheese, half of the mozzarella, garlic powder, Italian seasoning, salt, and pepper.

Spread a thin layer of white sauce at the bottom of the baking dish. Layer three lasagna noodles, half the chicken filling, half the spinach, and a third of the remaining sauce.

Repeat the layering process with three more noodles, the remaining chicken filling, the rest of the spinach, and half of the remaining sauce.

Top with the last three noodles, the remaining white sauce, and sprinkle the remaining mozzarella and Parmesan cheese.

Cover the baking dish with aluminum foil and bake for 25 minutes.

Remove the foil and bake for an additional 15 minutes or until the top is golden and bubbly.

Let the lasagna sit for 10-15 minutes before slicing to help it hold its shape.