Preheat the oven to 375 degrees F (or 190 degrees C). Lightly grease a 9x13 inch baking pan with olive oil or cooking spray and set aside. Set a deep skillet or dutch oven over medium-high heat on the stove top and add olive oil, ground beef, and diced yellow onion.
Sauté, breaking up the beef with a spatula or spoon, for 6-8 minutes or until beef is no longer pink.
Add the minced garlic, salt, and pepper and sauté for an additional 1-2 minutes, stirring often to make sure the garlic does not burn.
Add the marinara sauce and stir to combine. Let cook for an additional 5 minutes, then remove from the heat and set aside.
In a large bowl, combine the ricotta cheese, egg, salt, pepper, parmesan cheese, 1 cup of the mozzarella cheese, and fresh chopped parsley. Reserve the remaining 1 cup of mozzarella cheese for later. Stir the ricotta mixture until well combined.
To assemble the lasagna, place 1 cup of meat sauce in the bottom of the prepared baking pan and spread with a spoon or spatula until the entire pan is covered.
Place ⅓ of the gluten-free lasagne noodles in a layer on top of the sauce. Depending on the size and shape of your lasagne noodles, you will be able to fit 4-5 noodles in a layer. Break up lasagne noodles as needed to cover the entire pan. With Barilla Gluten-Free Lasagne Noodles, I was able to fit four noodles next to each other and then broke up a fifth noodle to fill the entire space.
Add approximately 1/2 of the ricotta cheese mixture to the top of the noodles, and gently spread across the noodles so that it is evenly distributed.
Top the cheese with 1 cup of sauce, then lasagne noodles, then ricotta cheese again, all evenly distributed. Repeat one more time, finishing with a final layer of sauce. Sprinkle remaining 1 cup of mozzarella cheese evenly over the sauce. To recap, the order from bottom to top goes 1 cup sauce, ⅓ of the noodles, ½ the ricotta, 1 cup sauce, ⅓ of the noodles, ½ of the ricotta, 1 cup sauce, ⅓ of the noodles, remaining sauce, 1 cup of mozzarella (see diagram above in post).
Spray a piece of aluminum foil on one side and cover the baking dish with foil, sprayed side down. Bake at 375F (190C) for 45 minutes.
Remove foil and bake for an additional 10 minutes, until the sauce is bubbling and cheese is melted.
Remove lasagna from the oven and let cool for 10-15 minutes before cutting and serving. Top with additional fresh parsley, if you desire.