In a large skillet, cook beef over medium heat until no longer pink; drain.
In a medium bowl, mix together ricotta cheese, spinach, egg, garlic powder, onion powder, and pepper.
Spread 1 cup spaghetti sauce in the bottom of a 9x13 inch baking dish.
Arrange 4 noodles over sauce; top with half of the beef, half of the ricotta mixture, and 1 cup spaghetti sauce. Repeat layers, and top with remaining noodles and sauce.
Sprinkle with mozzarella cheese.
Bake in preheated oven for 30 minutes, or until cheese is melted and bubbly.
Interesting Facts
Lasagna is an Italian dish that is traditionally made with layers of pasta, cheese, and sauce.
The word "lasagna" comes from the Greek word "lasanon" which means "chamber pot".
Lasagna can be made with a variety of ingredients, including vegetables, seafood, and meats.