Start by patting the chicken breasts dry with paper towels. Season both sides generously with salt, pepper, garlic powder, onion powder, and dried thyme.
Heat 2 tablespoons of olive oil in a large skillet over medium-high heat. Once hot, add the chicken breasts and cook for about 5-6 minutes on each side, or until golden brown and cooked through. Remove the chicken from the pan and set aside on a plate, keeping it warm.
In the same skillet, add the sliced mushrooms. Sauté them for 4-5 minutes until they release their moisture and become golden brown.
Pour in 1 cup of chicken broth to deglaze the pan, scraping up the browned bits with a wooden spoon. Let the broth reduce slightly, about 2-3 minutes. Then stir in 1 cup of heavy cream and bring the mixture to a gentle simmer. Allow it to thicken slightly, about 4-5 minutes, stirring occasionally.
Return the chicken breasts to the skillet, nestling them into the creamy mushroom sauce. Spoon some sauce over each breast. Let everything simmer together for another 5 minutes on low heat so the flavors meld perfectly.
While the chicken finishes cooking, bring a medium pot of salted water to a boil. Add the 12 ounces of egg noodles and cook according to package instructions until al dente. Drain the noodles in a colander.
Return the drained noodles to the pot. Stir in 2 tablespoons of butter until melted and evenly coating the noodles.
Divide the buttered noodles between plates. Top with a chicken breast and generous spoonfuls of the creamy mushroom marsala sauce. Sprinkle freshly chopped parsley on top for a vibrant, fresh finish.
