Cut the chicken into bite-sized pieces. Season the chicken with salt, pepper and garlic powder. Lightly season the sliced mushrooms with salt and pepper.
While you are making the creamy chicken marsala, boil your pasta according to the package instructions and drain when finished. Make sure that you add salt to your pasta water.
In a large saute pan, heat 2 tablespoons of olive oil over medium heat. Cook the chicken pieces, stirring for even browning until fully cooked, for about 8 minutes but times may vary. Transfer the cooked chicken to a plate and tent with foil to keep warm. Do not wipe the pan down.
In the same pan, add 1 tablespoon of olive oil over medium heat, melt in 2 tablespoons of butter. Add the seasoned sliced mushrooms to the pan and saute for 8 minutes, stirring occasionally, until they are golden. Transfer the sauteed mushrooms to the plate with the cooked chicken. Tent with foil to keep warm.
Use the same pan to make the sauce, do not wipe it down. Add the marsala wine to the pan to deglaze it, scraping up the browned bits, and simmer for about 2 minutes. Add the last 3 tablespoons of butter and minced garlic to the pan. Cook for about 1 to 2 minutes, or until the butter is completely melted and the garlic is fragrant, whisk to combine. Stir in the heavy cream and bring to a simmer. Keep at a simmer for 5 minutes. Reduce the heat to low then add the parmesan cheese to the pan and whisk quickly to combine, just heating through.
Stir in the cooked pasta, then return the chicken and mushrooms to the pan. Stir to combine until just heated through. Transfer to a serving dish and garnish with fresh parsley and extra cheese if you would like. Serve hot and enjoy!