Preheat the oven to 375°F (190°C). Lightly grease a 9×13-inch baking dish.
Cook the ground beef in a large skillet over medium heat until browned. Drain excess grease.
Add the diced onion and cook for 4 to 5 minutes until softened. Stir in the garlic and cook for 30 seconds.
Add the marinara sauce, tomato sauce, Italian seasoning, garlic powder, onion powder, salt, and pepper. Simmer for 10 minutes.
In a medium bowl, combine the ricotta cheese, egg, Parmesan cheese, parsley, salt, and pepper until smooth.
Spread a thin layer of meat sauce on the bottom of the baking dish.
Arrange a layer of cooked lasagna noodles over the sauce.
Spread one-third of the ricotta mixture over the noodles, then spoon on one-third of the meat sauce and sprinkle with mozzarella cheese.
Repeat the layers two more times.
Finish with the remaining noodles, meat sauce, mozzarella, and Parmesan cheese.
Cover loosely with foil and bake for 35 minutes.
Remove the foil and bake for another 15 to 20 minutes until the cheese is golden and bubbly.
Let the lasagna rest for 15 minutes before slicing and serving.
Garnish with chopped parsley.