Season the turkey with salt and pepper. Brush the cutlets lightly with the mayonnaise. Combine the breadcrumbs, Parmesan cheese and sage on a large plate. Coat each cutlet in the breadcrumb mixture; gently press the breadcrumbs on to help them adhere.
Place the pasta sauce in a small pot and warm over medium-low heat. Set the oven rack 6" beneath the broiler; preheat the broiler. Heat the oil in a large skillet set over medium heat. Cook the breaded turkey 3 to 4 minutes per side, or until cooked through, then place on a baking sheet and top each with an equal amount of mozzarella cheese. Broil until the cheese melts. Serve the cutlets on a pool of the warmed pasta sauce.