Bring a large pot of water to boil, and cook the lasagna noodles according to the package directions. Drain and set aside.
In a large skillet over medium-high heat, add the sausage and onions. Break apart the sausage and cook for 7-8 minutes until the meat is cooked and the onions are soft. Drain away the grease. Add the garlic and cook for 1-2 minutes until you can start to smell it.
Pour in the marinara sauce and simmer for a few minutes.
Meanwhile in a large bowl mix together ricotta cheese, 2 cups Mozzarella cheese, Parmesan cheese, egg, and Italian seasoning.
Preheat oven to 350º F. Spread about ½ cup sauce over the bottom of a 13x9 inch baking dish.
Lay the lasagna noodles on a tray in front of you. Spread 2-3 Tablespoons over each lasagna noodle, followed by about 3 Tablespoons of meat sauce. Roll up and place seam side down in a baking dish.
Pour the remaining meat sauce over the roll ups, and sprinkle with the rest of the cheese. Cover with foil (spray with non-stick spray to help the cheese not stick). Bake for 35-40 minutes until hot and bubbly. Remove the foil and cook for 5 more minutes to brown the cheese.
Garnish with fresh basil and more Parmesan cheese if desired.
