Cook the PastaBring a large pot of salted water to a boil. Cook pasta until just shy of al dente (about 1–2 minutes less than package instructions). Drain and set aside.
Sear the ChickenHeat olive oil in a large skillet over medium-high heat. Season diced chicken with salt, pepper, and Italian seasoning. Sear until golden and cooked through, 5–7 minutes. Remove from pan.
Build the SauceIn the same skillet, sauté garlic until fragrant (about 1 minute). Stir in marinara sauce and heavy cream. Simmer for 3–4 minutes until slightly thickened.
Combine IngredientsAdd spinach to the sauce, stirring until wilted. Mix in the cooked pasta and chicken, tossing until well coated.
Assemble the BakeTransfer mixture to a greased 9x13-inch baking dish. Sprinkle mozzarella and Parmesan evenly on top.
Bake & FinishBake at 375°F (190°C) for 15–20 minutes until cheese is melted and bubbly. For a golden crust, broil for 2–3 minutes at the end.
ServeGarnish with fresh basil if desired and serve hot.
