Brown the ground beef with onion in a large skillet, then drain any excess fat. Stir in garlic, crushed tomatoes, tomato paste, and seasonings; simmer to create a rich meat sauce.

In a separate bowl, combine ricotta cheese, grated Parmesan, egg, and fresh parsley with salt and pepper to form the creamy cheese mixture.

Spread a thin layer of meat sauce in the bottom of a 9x13 inch baking dish; then arrange a single layer of lasagna noodles over the sauce.

Top the noodles with half of the ricotta mixture, followed by a layer of meat sauce and a generous sprinkle of shredded mozzarella cheese.

Repeat the layering process once more with noodles, the remaining ricotta, more meat sauce, and mozzarella.

Finish the lasagna with a final layer of noodles, the remaining meat sauce, and sprinkle with the last of the shredded mozzarella and a bit more Parmesan cheese.

Bake the lasagna in a preheated oven at 375°F (190°C) for 45-50 minutes, or until bubbly and the cheese is golden brown.

Let the lasagna rest for 10-15 minutes after serving to ensure the layers set properly and for easier slicing.