Cook the pasta: Bring a large pot of generously salted water to a boil. Cook the penne according to package directions until al dente. Drain and set aside.

Sauté the mushrooms: Heat 1 tablespoon olive oil in a large oven-safe skillet over medium heat. Add the sliced mushrooms and cook for 4 to 5 minutes, stirring occasionally, until browned and tender.

Add the spinach and chicken: Stir in the fresh spinach and cook until wilted, about 1 to 2 minutes. Add the cooked chicken along with the salt, black pepper, garlic powder, and Italian seasoning. Stir to combine.

Build the sauce: Pour in the marinara sauce and stir well. Reduce the heat slightly and let the mixture simmer for 3 to 4 minutes. Stir in the heavy cream and lemon zest, then cook for another 1 to 2 minutes until the sauce is warmed through and slightly creamy. Taste and adjust the seasoning as needed.

Combine with pasta: Add the cooked penne to the skillet and toss until the pasta is evenly coated with the sauce. Sprinkle the mozzarella and 1/4 cup Parmesan cheese evenly over the top.

Prepare the breadcrumb topping: In a small skillet, heat 1 tablespoon olive oil over medium heat. Add the breadcrumbs, 2 tablespoons Parmesan cheese, and the lemon zest. Cook for 2 to 3 minutes, stirring frequently, until the breadcrumbs are golden brown and fragrant.

Melt the cheese: If using an oven-safe skillet, place the skillet under the broiler for 2 to 3 minutes, or until the cheese is melted and bubbly. If not using an oven-safe skillet, cover with a lid and allow the cheese to melt over low heat.

Finish and serve: Sprinkle the toasted lemon-Parmesan breadcrumbs over the top just before serving. Garnish with additional Parmesan cheese and fresh basil, if desired.