Preheat your oven to 350°F (175°C).

Start by preparing the filling for the manicotti. Cook the chicken breasts in a large skillet over medium-high heat until they are cooked through. Remove the chicken from the skillet and shred it using two forks.

In the same skillet, sauté the spinach over medium heat until it is wilted. Remove the spinach from the skillet and set it aside to cool.

In a large bowl, combine the shredded chicken, wilted spinach, ricotta cheese, Parmesan cheese, parsley, basil, minced garlic, and salt and pepper. Mix well to combine.

Lay the crepes out on a flat surface. Spoon about 1/2 cup of the chicken and spinach mixture onto the center of each crepe. Roll the crepes up tightly and place them seam-side down in a large baking dish.

Pour the tomato sauce over the top of the rolled crepes. Sprinkle with a little bit of Parmesan cheese, if desired.

Cover the baking dish with aluminum foil and bake for 20 minutes. Remove the foil and bake for an additional 10 minutes, or until the crepes are hot and the cheese is melted and bubbly.