In a large skillet over medium heat, brown 1 pound of ground beef until fully cooked, about 5-7 minutes. Drain any excess fat, then stir in 3 cups of marinara sauce and season with Italian seasoning and garlic powder. Allow the sauce to simmer for 10 minutes.

While the sauce simmers, combine 15 oz of ricotta cheese, 1 egg, and a sprinkle of salt and pepper in a mixing bowl. Mix until smooth and creamy.

Preheat your oven to 375°F (190°C). Start layering ingredients in a 9x13 inch baking dish with a layer of meat sauce, followed by lasagna noodles, half of the cheese mixture, and 2 cups of shredded mozzarella. Repeat until all ingredients are used, finishing with mozzarella and Parmesan on top.

Place the assembled lasagna in the preheated oven and bake for 45-55 minutes until golden and bubbly. Cover with foil if browning too quickly.

Once baked, let the lasagna cool for about 10 minutes before serving to allow layers to set.