In a large skillet, heat a drizzle of olive oil over medium heat and brown the ground beef with a chopped onion for about 5-7 minutes, until the meat is no longer pink and the onions are translucent. Drain any excess fat.

Add minced garlic and stir for another minute until fragrant. Mix in tomato paste, crushed tomatoes, tomato sauce, dried basil, oregano, sugar, salt, and pepper. Allow the mixture to simmer for 25-30 minutes until thickened.

In a medium bowl, combine ricotta cheese, beaten egg, grated Parmesan cheese, and chopped parsley. Stir until well blended and creamy.

Preheat your oven to 375°F (190°C). In a deep baking dish, spread a layer of the prepared meat sauce at the bottom, followed by lasagna noodles, ricotta mixture, and a sprinkle of mozzarella. Repeat until you reach the top, ending with noodles topped with remaining meat sauce and mozzarella.

Cover the assembled lasagna with aluminum foil and bake for 25 minutes. Remove the foil and bake for an additional 20 minutes until bubbly and golden brown.

Let the lasagna rest for about 15 minutes before slicing to allow the layers to set.