Bring a large pot of salted water to boil and cook the pasta.
Spinach thawing tip - I set my frozen spinach in the fridge overnight so it wasn't fully frozen when I was ready to use it today. From that point, I finished defrosting it in the microwave for about 3 minutes in a microwave safe bowl. Put another bowl, the same size, on top of the spinach bowl and gently squeeze together to drain the excess water. Does that visual work for you? It worked really well and was easier than wringing it out in paper towel.
Drain the pasta then return it to the pot. Add in the cooking creme, spinach, dried basil, dried onion and sprinkle of Italian cheese blend. Mix until fully combined.
Cover the bottom of an 8 x 8 baking dish with marinara sauce then top with the spinach pasta mixture. Pour the remaining sauce over the top. Sprinkle with the 1/2 cup of mozzarella cheese and top with freshly ground black pepper.
Bake for approximately 20-30 minutes until cheese is browned. Serve hot.