Pound the chicken cutlets to 1/4-inch thickness. Whisk together the flour, garlic powder, onion powder, salt, and pepper in a shallow bowl. Dredge each cutlet in the flour mixture and shake off the excess.

Heat the olive oil and 1 tbsp butter in a large skillet over medium-high heat. Sear the cutlets 3 to 4 minutes per side until golden and cooked to 165°F (74°C). Transfer to a plate and tent with foil.

Reduce heat to medium. Melt the remaining 1 tbsp butter in the same pan. Cook the mushrooms undisturbed for 3 minutes, stir, and cook another 2 minutes. Add the garlic and cook for 30 seconds.

Pour in the Marsala wine, scrape up the browned bits, and simmer for 2 minutes until reduced by half. Add the chicken broth and heavy cream. Simmer for 5 to 6 minutes until the sauce coats the back of a spoon.

Return the chicken to the pan and warm through for 2 minutes over low heat. Spoon the sauce and mushrooms over the cutlets, plate, and scatter fresh parsley over the top.