Preparation: Preheat the oven to 350°F and grease a 9x13-inch baking dish with butter or nonstick spray. Set aside. Place lasagna noodles in a separate 9x13-inch dish and cover with hot water to soak while preparing the sauce, ensuring to agitate occasionally to prevent sticking.

Sauté Aromatics: In a large skillet over medium-high heat, melt butter. Add onion and cook until translucent, about 10 minutes. Add minced garlic and cook for an additional 2 minutes, stirring frequently.

Add Spinach and Prepare Sauce: Stir in fresh baby spinach and cook until wilted. Pour in heavy cream, add dried basil, kosher salt, and freshly ground black pepper to taste. Bring the mixture to a simmer, then stir in freshly grated Parmesan cheese and ricotta cheese until melted and well combined. Add shredded chicken breast and adjust sauce thickness as needed by simmering for a few minutes if too liquid.

Layering: Spread a thin layer of the Alfredo sauce mixture on the bottom of the prepared baking dish. Arrange a layer of soaked lasagna noodles over the sauce. Top with about one-third of the Alfredo sauce mixture, followed by one-third of the grated mozzarella cheese. Repeat layers until all ingredients are used, ensuring that mozzarella cheese is the top layer.

Baking: Cover the baking dish with foil and bake in the preheated oven for 45 minutes. Uncover and broil for an additional 2-3 minutes to brown the cheese on top.

Rest and Serve: Remove from the oven and let the pasta bake rest for 10 minutes before serving. Garnish with minced fresh parsley if desired. Enjoy this creamy and comforting Chicken Alfredo Pasta Bake!