Place the chicken, marinara, broth, basil and salt in a covered skillet and bring the sauce to a gentle simmer.
Cook over medium-low heat for 18 to 24 minutes, turning once, until the chicken reaches 165°F.
Shred the chicken with 2 forks and stir it back into the sauce, simmering uncovered for 3 minutes until thick enough to mound.
Heat the broiler and stir the melted butter with garlic powder.
Brush the cut rolls with garlic butter, broil for 1 minute and divide the saucy chicken among the bottom halves.
Top with mozzarella and Parmesan, broil for 1 to 2 minutes until browned and bubbling and close the sandwiches with the toasted roll tops.