In a large pot, bring salted water to a boil. Add the penne pasta and cook according to package instructions until al dente. Drain and set aside, reserving 1/2 cup of pasta water.
In a large skillet, heat olive oil over medium heat. Add the diced chicken and season with salt, pepper, and Italian seasoning. Cook for about 5-7 minutes, or until the chicken is browned and cooked through.
Stir in the minced garlic and cook for 1 minute until fragrant. Add the cherry tomatoes and chopped spinach to the skillet. Sauté for another 3-4 minutes until the spinach wilts and the tomatoes soften.
Lower the heat, then add the heavy cream and stir to combine. Gradually mix in the Parmesan cheese until melted and creamy. If the sauce is too thick, add reserved pasta water a little at a time until you reach the desired consistency.
Add the cooked penne to the skillet, tossing the pasta to combine it with the sauce and other ingredients. Allow everything to heat through for another 2-3 minutes. Adjust seasoning with salt, pepper, and red pepper flakes if desired.
Plate the Spinach Chicken Pasta into bowls and optionally, sprinkle more Parmesan on top for garnish.
Notes
Add crushed red pepper flakes for extra heat if desired.