Cook the Pasta. Bring a large pot of salted water to a boil. Cook the penne pasta according to the package instructions until al dente. Drain and set aside, reserving ½ cup of the pasta water (if needed for pasta sauce).
Prepare the Chicken. In a large skillet, heat the olive oil over medium-high heat. Season the chicken pieces with salt, black pepper, and paprika. Add the chicken to the skillet and sear on all sides until golden brown and cooked through about 6–8 minutes. Transfer the chicken to a plate and set aside.
Sauté the Aromatics. In the same skillet, reduce the heat to medium and melt the butter. Add the minced garlic and sliced red onion, cooking until fragrant and softened, about 2–3 minutes.
Deglaze the Pan. Pour in the white wine and simmer for 1–2 minutes, scraping up any browned bits from the bottom of the skillet. Add the chicken broth and sun-dried tomatoes, stirring to combine. Simmer for another 2 minutes to enhance the flavors.
Make the Creamy Sauce. Stir in the heavy cream, grated Parmesan cheese, and Italian seasoning. Simmer gently for 4–5 minutes, stirring occasionally, until the sauce thickens slightly. Season with salt and freshly ground black pepper to taste.
Combine Chicken and Spinach. Return the cooked chicken to the skillet along with the spinach leaves. Stir until the spinach wilts and the chicken is warmed through, about 2–3 minutes.
Toss with Pasta. Add the cooked pasta to the skillet, tossing to coat evenly in the sauce. If the sauce is too thick, add the reserved pasta water, one tablespoon at a time, until the desired consistency is achieved.
Serve. Transfer the Marry Me Chicken Pasta to a serving dish. Garnish with fresh basil, additional Parmesan cheese, and crushed red pepper flakes if desired. Serve immediately and enjoy!