Preheat oven to 375 degrees. Coat a 8×8 baking dish with non-stick cooking spray. Place chicken breasts between two sheets of saran wrap (or in a large ziplock bag), and each pound chicken breast with meat pounder, (or rolling pin) until chicken is about 1/4 inch thick.
Meanwhile, mix together the spinach, feta, parmesan, cottage cheese, and seasoning in a small bowl. Lay the chicken breasts out on a clean surface, and evenly divide the spinach mixture between each chicken breast.
Roll up the chicken to enclose the spinach and cheese mixture, and arrange chicken in the baking dish, seam side down. (You could also secure each chicken breast with a toothpick). Pour marinara sauce evenly over the stuffed chicken breasts. Sprinkle 1/4 cup parmesan cheese over the top if desired.
Bake for 35 minutes in preheated oven. Turn the heat up to 500 degrees, or turn on your oven?s broiler to brown the parmesan cheese for an additional 2-5 minutes. Remove chicken from the oven and enjoy with additional marinara sauce if desired!