Bring a large pot of salted water to a rolling boil. Add the pasta and cook until al dente according to package directions. Carefully remove 1 cup of the cooking water and set aside. Drain the pasta.
Be sure to reserve 1 cup of the pasta cooking water, as you'll use this to make the sauce.
While the pasta cooks, in a medium bowl combine the chicken with 2 teaspoons paprika, 2 teaspoons of the granulated garlic, 2 teaspoons of the thyme, and 1 teaspoon of the salt, tossing the chicken to coat evenly in the spices.
Heat a large, heavy-bottom pot such as a Dutch oven over medium-high heat.
Add 1 tablespoon of the olive oil, then add the seasoned chicken and cook until golden on all sides, but not quite cooked through, about 5 minutes. Transfer to a medium bowl and set aside.
To the same pan (no need to wash it first), add 1 tablespoon olive oil, the onion, 1 teaspoon of granulated garlic, 1 teaspoon of thyme, ¼ teaspoon of salt, and ¼ teaspoon black pepper.
Cook until the onion is soft and translucent, about 5 minutes, stirring frequently.
Add the tomato paste and cook for 30 more seconds, stirring constantly.
Add the chicken stock, ¼ teaspoon of salt, sugar, and sun dried tomatoes to the pan. Bring to a strong simmer, scraping any browned bits from the bottom of the pan.
To the simmering sauce, add the chicken along with any accumulated juices, heavy cream, parmesan cheese, and cream cheese. Simmer over low heat and stir until the ingredients are incorporated, the sauce is smooth, and the chicken is cooked through, about 2-3 minutes.
Add the cooked pasta along with ¼ cup of the pasta cooking water, tossing the pasta to coat in the sauce.
Turn off the heat and add the spinach and vinegar, stirring to wilt the spinach. Taste and adjust seasonings if necessary, adding additional pasta to thin the sauce if needed.
Notes
Chicken: Breasts and thighs work equally well here, based on your preference. Just be sure not to overcook the chicken in step 3 (no one wants dry chicken!) since it'll continue cooking in the simmering sauce.
Pasta Water: Reserve a cup of starchy pasta water & just add a little at a time until your sauce is the perfect creamy consistency that you want.
Tomato Paste: If you have leftover tomato paste it freezes well, so just transfer it to a small zip-top bag for the next time you make this recipe. Or, use the kind in the tube! Just remember most tomato paste in a tube is double concentrated, so you'll just need half the amount called for in the recipe.