For the meat layer: Heat an ovenproof skillet over medium-high heat; add the oil. Once the oil is hot, add the ground beef, celery, onion, and garlic. Cook, breaking up the meat with a wooden spoon, until no longer pink, 5 to 6 minutes.
Stir in the marinara sauce, salt, and pepper. Reduce heat to low. Simmer, stirring occasionally, while you make the cheese layer.
In a large bowl, stir together the ricotta, half of the mozzarella, the Parmesan, eggs, Italian seasoning, minced garlic, garlic powder, and pepper. Spread the cheese mixture over the top of the meat mixture.
Sprinkle with the remaining mozzarella cheese.
Cover and cook on medium-low heat until the cheese is hot and cooked through, 10 to 15 minutes. Meanwhile, preheat the broiler. Broil lasagna until top is browned, 2 to 3 minutes. Let stand 10 minutes before serving.