Preheat oven to 375°F.
In a skillet, cook the ground beef over medium heat until browned and cooked through, 5-7 minutes. Drain any excess fat.
In a bowl, mix together the cooked ground beef, ricotta cheese, ½ cup of the mozzarella cheese, parmesan cheese, egg, and oregano until well combined.
Spread the beef mixture evenly onto 8 lasagna noodles. Roll up the noodles and place seam-side down in a baking dish.
Top the lasagna rolls with the remaining ½ cup mozzarella cheese.
Bake for 15 minutes, or until the cheese is melted and bubbly.