Cook the ground beef and Italian sausage in a skillet until browned. Drain excess fat.
Mix ricotta cheese, egg, Italian seasoning, salt, and pepper in a bowl.
Spread a thin layer of spaghetti sauce in a baking dish. Place three lasagna noodles over the sauce, then add half of the ricotta mixture, a portion of the meat mixture, and a layer of mozzarella. Repeat the layers, finishing with noodles, sauce, and mozzarella.
Cover with foil and bake for 25 minutes.
Remove foil and bake for an additional 15 minutes or until cheese is bubbly and golden.
Let cool for 10 minutes before slicing and serving.
Notes
Feel free to substitute the meat for sautéed mushrooms, spinach, and zucchini for a vegetarian option.