In a large skillet over medium heat, cook the 1 pound ground beef and diced onion together for 6–8 minutes, breaking the meat apart as it cooks. Continue until the beef is browned and the onions are soft. Drain excess grease if needed.
Stir in 4 cups marinara sauce, ½ teaspoon salt, and ½ teaspoon black pepper. Simmer on low for 5–10 minutes until slightly thickened.
Preheat oven to 375°F. Lightly grease a 9×13 baking dish.
Spread a thin layer of meat sauce on the bottom of the dish. Add a layer of noodles, then meat sauce, then a layer of mozzarella cheese. Repeat layers until ingredients are used, finishing with the remaining mozzarella on top.
Bake uncovered for 30–35 minutes, or until cheese is melted, bubbly, and lightly golden around the edges.
Rest before serving.
Let the lasagna rest for 10 minutes before slicing so the layers hold together.
Video
Notes
When it comes to the nutrition information provided for recipes, it’s important to keep in mind that it’s just an estimate. The actual nutritional values can vary based on the specific ingredients and brands you use. Be mindful that any nutritional information provided is intended as a general guideline rather than exact values.
Slightly undercook noodles so they don’t become mushy while baking.
Resting time helps layers set and slice cleanly.
If sauce thickens too much, stir in a few tablespoons of water before layering.