Preheat oven to 350. Grease an 8X8 casserole dish.
Cook beef in a large skillet until no longer pink. Add sauce. Using the empty sauce jar, add 1 jar full of water to beef mixture. Stir well.
In a separate bowl, combine cottage cheese, 1 cup mozzarella, eggs, salt, and pepper. Stir well.
Place 1 cup beef mixture in the bottom of the casserole dish. Top with 1/2 the noodles. Spread 1/2 the cheese mixture on top of noodles. Top with 2 cups beef mixture, remaining noodles, and remaining cheese mixture. Pour any remaining sauce over the top. Sprinkle with remaining mozzarella cheese.
Bake, covered, 30 minutes. Uncover and bake 30 min longer or until casserole is bubbly and noodles are cooked.