In an extra-large skillet (or saucepot), on medium-high heat, add your olive oil, chopped onions, minced garlic, Italian seasoning blend, salt, and black pepper. Saute for 2-3 minutes or until the onions start to get tender. Push your cooked onions and spices to the side of your skillet and add your ground beef.
Cook your beef for another 5-7 minutes or until it is cooked thoroughly and no pink remains in the meat. Stir your cooked onions into your cooked beef. Drain any excess fat if desired before moving on to the next step.
Add the tomato paste to the beef mixture and stir it around until it is completely incorporated.
Add the crushed tomatoes, stir and turn your heat to low to simmer for 20-30 minutes while you prepare the rest of your ingredients. Note: Taste your sauce to see if you need to add any more salt and pepper. This is a personal preference as some brands of can tomatoes can be saltier than others.
Once your sauce has simmered, turn off the heat and add the 1 tablespoon of fresh chopped parsley and stir. Set aside until ready to assemble your lasagna.
While your sauce is simmering, boil your lasagna noodles for only 5 minutes. You want them to just be partially cooked. Drain the pasta water from the pot and leave your noodles in the warm pot while you are assembling the lasagna.
In a medium-sized mixing bowl add your ricotta cheese, 2 cups mozzarella cheese, 1 ½ cups shredded parmesan cheese, egg, and fresh chopped parsley. Stir to combine.
Preheat oven to 350* F. Lightly spray, with cooking spray, a deep dish 9x13 casserole pan (also known as a lasagna pan). **If you do not use a deep dish then your lasagna may bubble up and overflow a standard 9x13 pan while cooking in the oven**
Layering your lasagna: start by adding 1 ½ -2 cups of sauce into the bottom of the pan and spreading it evenly.
Next add a layer of 5-6 noodles (they should be slightly overlapping and you can trim them to fit your pan).
Then you will layer ½ of your cheese filling evenly over the noodle layer.
Once your cheese layer is spread out, very gently spoon over 2 cups of sauce. Do not mix the sauce into the cheese layer, just gently smooth it over.
Repeat with another layer of noodles, the other half of the cheese mixture, and another 2 cups of sauce. You will top that with the remaining noodles, then the remaining sauce. You will top your lasagna with the remaining 1 cup mozzarella and ½ cup shredded parmesan cheese.
Cover your lasagna dish with aluminum foil (you can lightly spray your aluminum foil with some cooking spray, on the side that will be facing the cheese to keep the cheese from sticking when baking) and bake it for 30 minutes, then remove the foil and continue to bake for another 30 minutes or until the cheese is lightly golden and bubbly.
Once your lasagna has cooked, allow it to cool on the counter for a minimum of 30 minutes, up to 45 minutes, before slicing and serving. It will still be nice and warm but you will get nice pretty slices (and not a lasagna mess all over your plate) by allowing it to rest and set up.