Preheat your oven to 375°F (190°C).
In a large skillet, heat the olive oil over medium heat. Add the ground beef and cook until browned, breaking it apart with a spoon, about 5-7 minutes. Drain excess fat if necessary.
Stir in the garlic powder, onion powder, oregano, salt, and pepper. Remove from heat and let it cool slightly.
In a mixing bowl, combine the ricotta cheese, half of the mozzarella cheese, Parmesan cheese, and egg. Mix until well combined.
Carefully fill each cannelloni tube with the beef mixture using a small spoon or piping bag.
Spread 1 cup of marinara sauce on the bottom of a 9x13 inch baking dish. Arrange the filled cannelloni on top of the sauce.
Pour the remaining marinara sauce over the cannelloni, ensuring they are well covered.
Sprinkle the remaining mozzarella cheese on top.
Cover the baking dish with aluminum foil and bake for 25 minutes. Remove the foil and bake for an additional 10-15 minutes, or until the cheese is bubbly and golden.
Let it cool for a few minutes before serving. Garnish with fresh basil leaves if desired.
