Place 9 sheets of lasagna noodles in a heat-proof dish and pour very hot water over them to soak. Let them sit while you prepare the other ingredients. This softens the noodles, making them pliable and ready for assembly without boiling. I find soaking the noodles saves time and makes the layers come out extra tender.

In a large skillet over medium-high heat, brown the ground beef until fully cooked, breaking it up with a spatula as it cooks. Drain excess fat from the pan, then add the chopped onion. Sauté for an additional 2 minutes until the onion is slightly softened. This step builds the savory base for your lasagna.

Reduce the heat to medium, and add the jarred pasta sauce and ricotta cheese to the skillet with the beef and onion mixture. Stir thoroughly to combine and heat the mixture until warmed through. The ricotta gives the sauce a rich, creamy texture.

Preheat your oven to 350°F (175°C). In a 13 by 9-inch baking pan, ladle enough of the sauce mixture to thinly cover the bottom. Place 3 soaked lasagna noodles (from Step 1) evenly over the sauce. Top with about 2 cups of the sauce mixture (from Step 3), 3/4 cup shredded mozzarella, and 1/4 cup grated parmesan. Repeat this layering process two more times until all ingredients are used, ending with a cheese layer. For the creamiest top, I like to save a little extra mozzarella and parmesan for the final layer.

Cover the assembled lasagna tightly with aluminum foil and bake in the preheated oven at 350°F for 45-55 minutes. The cheese should be melted and bubbly, and the center heated through. For a golden topping, you can uncover the lasagna and broil it for 2-3 minutes at the end. Let it cool for 10-15 minutes before slicing to allow the layers to set—I always let it rest so it slices neatly.