Preheat oven to 375 degrees Fahrenheit. Boil 12 lasagna noodles according to package directions, then drain.

In a skillet, brown 1 lb of ground beef over medium heat until fully cooked. Drain excess fat and stir in 24 oz of tomato sauce.

In a bowl, mix 15 oz of ricotta cheese, 0.25 cups of parmesan cheese, and 2 tbsp chopped fresh parsley.

Spread a thin layer of meat sauce in a 9x13 inch baking dish. Layer 3 noodles, one third of the ricotta mixture, one cup of mozzarella, and more meat sauce. Repeat layers twice.

Top with remaining noodles, meat sauce, remaining mozzarella, and remaining 0.25 cups of parmesan cheese.

Cover with foil and bake for 25 minutes. Remove foil and bake an additional 25 minutes until the cheese is melted and bubbly. Let rest 15 minutes before slicing.