Adjust an oven rack to the middle position, and preheat the oven to 350°F. Spray a 9x13-inch casserole dish with nonstick cooking spray.
Place 1 cup of marinara sauce in the bottom of the casserole dish and set the chicken, evenly, on top.
32 oz. marinara sauce, 12 boneless, skinless chicken tenders
Pour the remaining sauce over the chicken.
Bake the chicken at 350°F for 30-45 minutes, or until the internal temperature of the chicken is 155°F. The baking time will depend on the size of the chicken breasts.
While the chicken bakes, boil the spaghetti per package directions and drain.
16 oz. dry spaghetti
Remove the chicken from the oven and set the oven to Broil.
Place a small mound of Mozzarella cheese over each piece of chicken and sprinkle the Mozzarella with Parmesan. Return the chicken to the oven. Broil the chicken (watch closely) just until the cheese has melted and the internal temperature of the chicken registers 160-165°F with a meat thermometer.
2-3 cups freshly shredded mozzarella cheese, ¼ cup freshly grated Parmesan cheese
Transfer the chicken to a cooling rack and let rest 5 minutes before serving.
Serve the chicken and sauce over a bed of cooked spaghetti. Sprinkle with chopped fresh basil and serve with extra grated Parmesan.
chopped fresh basil leaves