Here is my recipe for lasagna. I got it from America’s Test Kitchen.

Simple Lasagna with Hearty Tomato-Meat Sauce

tomato meat sauce
1 T olive oil
1 medium onion, chopped fine (about 1 cup)
6 med. garlic cloves, minced or pressed (about 2 T)
1/2 pound ground beef and 1/2 pound Italian sausage
1/2 t salt
1/2 t ground black pepper
1/4 cup heavy cream
1 (28 oz.) can pureed tomatoes
1 (28 oz.) can diced tomatoes, drained

ricottta, mozzarella, and pasta layers
15 oz. whole milk or part-skim ricotta cheese (1 3/4 cups)
1 1/4 cups grated Parmesan cheese
1/2 cup chopped fresh basil leaves
1 large egg, lightly beaten
1/2 t. salt
1/2 t. ground black pepper
12 no-boil lasagna noodles (the kind in the 8 or 9 oz. package)
16 oz. whole-milk (if you can find it) mozzarella cheese, shredded

1. Adjust oven rack to middle position and heat oven to 375.
2. Heat oil in large Dutch oven over medium heat until shimmering, about 2 minutes; add onions and cook, stirring occasionally, until softened but not browned, about 2 minutes. Add garlic and cook until fragrant, about 2 minutes. Increase heat to medium-high and add ground meats, salt,and pepper; cook, breaking meat into small pieces with spoon, until meat loses its raw color but has not browned, about 4 minutes. Add cream and simmer, stirring occasionally, until liquid evaporates and only fat remains, about 4 minutes. Add pureed and drained diced tomatoes and bring to simmer; reduce heat to low and simmer slowly until flavors are blended, about 3 minutes; set sauce aside. (Sauce can be cooled, covered, and refrigerated for 2 days/ reheat before assembling lasagna.)
3. Mix ricotta, 1 cup Parmesan, basil, egg, salt and pepper in medium bowl with fork until creamy; set aside.
4. Smear entire bottom of 13×9 baking dish with 1/4 cup meat sauce (avoiding large chunks of meat). Place 3 noodles in baking dish to create first layer. Drop 3 tablespoons ricotta mixture down ceter of each noodle and level domed mounds by pressing with back side of spoon. Sprinkle layer evenly with 1 cup shredded mozzarella cheese. Spoon 1 1/2 cups meat sauce evenly over cheese. Repeat layering of noodles, ricotta, mozzarella, and sauce two more times. Place 3 remaining noodles on top of sauce, spread remaining sauce over noodles, sprinkle with remaining 1 cup mozzarella, then with remaining 1/4 cup Parmesan. Lightly spray a large sheet of foil with nonstick cookin gspray and cover lasagna.
5. Bake 15 minutes, then remove foil. Return lasagna to oven and continue to bake until cheese is spotty grown and sauce is bubbling, about 25 minutes longer. Cool lasagna about 10 minutes; cut into pieces and serve.

If you want to make it ahead of time, the unbaked lasagna can be wrapped tightly in plastic wrap and then in foil and frozen for up to 2 months. Defrost it in the refrigerator for a day or two and bake as directed, extending the baking time by about 5 minutes.