Season the chicken breasts on both sides with salt and pepper.
Heat the oil in a large skillet over medium-high heat. Add the chicken to the skillet and cook until golden brown, approximately 4-5 minutes. Flip the chicken over and cook for an additional 4 minutes or until golden. Transfer the chicken to a plate and keep warm.
Add the butter to the pan and melt. Stir in the garlic and cook for 1 minute. Add the wine to the pan and deglaze by scraping up the brown bits with a wooden spoon. Turn the heat to low and simmer until the wine is reduced by half.
Stir in the chicken stock and bring to a simmer. Slowly stir in the half and half, cream cheese, garlic powder, onion powder and parmesan. Cook until the sauce is smooth and thick.
Stir in the spinach and cook for 1-2 minutes or until wilted. Return the chicken to the pan arranging so it's covered by the sauce and transfer to the oven.
Bake the chicken for 20 minutes or until an instant read thermometer registers 165˚F.
Season the sauce with salt and pepper to taste. Serve immediately with extra parmesan cheese, if desired.
Leftover chicken is great tossed with pasta for an easy Chicken Florentine Pasta recipe.