Boil a large, salted pot of water for your pasta and cook it al dente according to package instructions.
Meanwhile, cut the chicken in half lengthwise so you've got 4 thinner pieces. Season both sides of each piece with the garlic powder and salt & pepper.
Add the butter and olive oil to a skillet over medium-high heat. Let the pan heat up for a few minutes, then cook the chicken for about 5 minutes/side or until it's cooked through, then transfer the chicken to a plate.
Add the garlic to the skillet and cook for 30 seconds.
Add in the tomato paste, tomato sauce, cream, and Italian seasoning. Stir until it's nice and smooth. Reduce the heat to medium. Let the sauce cook for about 3-5 minutes (let it gently bubble and it will thicken up a bit).
Meanwhile, cut the chicken up into strips.
Season the sauce with some salt & pepper, then add in the chicken and spinach and let it warm through for a minute or two.
If the sauce gets too thick, add in a splash of the hot pasta water prior to draining it. Drain the pasta and toss with the sauce (I add the pasta back to the pot it was cooked in and then pour the skillet contents into the pot). Serve immediately with parmesan cheese over top.
