Heat the oven to 375°F (190°C). Brown the lean ground beef in a skillet over medium heat, breaking it into small pieces as it cooks. Drain excess fat, stir in the jarred pasta sauce, and warm the mixture.

Cook 9 regular lasagna noodles according to the package directions until just tender. Drain them carefully and avoid overcooking because they will continue cooking in the oven. Oven-ready noodles may be substituted; use approximately 9–12, depending on the brand.

Spread a thin layer of meat sauce in a 9-by-13-inch baking dish. Add noodles, about one-third of the ricotta, more meat sauce, and mozzarella, then repeat to make three layers, finishing with sauce and mozzarella on top.

Cover the baking dish tightly with foil and bake for about 25–30 minutes. Remove the foil and bake for another 10–15 minutes, until the cheese is melted and lightly browned.

Let the lasagna stand for 10–15 minutes before cutting. This resting time helps the layers set so each serving holds together more neatly.