Begin by preheating the oven to 350°F (175°C). Concurrently, grease a 9x13-inch baking dish using butter or nonstick spray. Set this aside for subsequent use.

Arrange the lasagna noodles in a separate 9x13-inch pan or a comparable long and shallow dish. Submerge the noodles completely by pouring hot water over them. Let them soak for a minimum of 30 minutes, periodically agitating them with your hands to prevent sticking.

Utilize a large skillet and heat it over medium-high heat. Commence by adding butter, followed by the chopped onion. Cook the onion until it reaches a translucent state, approximately 10 minutes. Subsequently, incorporate the minced garlic and continue cooking for an additional 2 minutes.

Introduce the fresh baby spinach into the skillet. Cook briefly, just until the spinach wilts.

Add the heavy cream to the skillet, along with dried basil, and a generous quantity of salt and pepper. Bring the mixture to a simmer. Following this, stir in the Parmesan and ricotta cheeses until they are thoroughly melted. Finally, integrate the shredded chicken into the mixture and remove the skillet from heat. If the mixture appears overly liquid, it may be simmered for a few more minutes to achieve the desired thickness.

Spread a spoonful of the Alfredo sauce mixture evenly across the bottom of the prepared baking dish. Over this sauce layer, arrange a layer of the pre-soaked noodles.

On top of the first noodle layer, apply approximately one-third of the Alfredo sauce mixture. Follow this with a layer of one-third of the grated mozzarella cheese. Continue this layering process until all ingredients are utilized, ensuring that mozzarella cheese forms the final top layer.

Cover the baking dish with foil and bake in the preheated oven for 45 minutes. For a browned cheese topping, optionally uncover the dish and broil for 2-3 minutes.

After baking, allow the lasagna to rest for 10 minutes before serving. This resting period is essential for the lasagna to set properly. Optionally, garnish with minced fresh parsley. Serve and enjoy.