Meanwhile, heat a large skillet over medium heat and add the ground beef and cook for about 5-7 minutes or until the meat is completely cooked through. Stir in the marinara sauce and remove from the heat.
To assemble the lasagna, spread a spoonful of the meat sauce in the bottom of a 7x11” baking dish. Add ½ of the ravioli evenly to the bottom of the pan, followed by ½ of the remaining meat sauce, and ½ of the shredded mozzarella. Repeat with one more layer of everything.
Pour the water over the top and cover the pan with foil. Bake covered for 40 minutes, then uncover and bake for an additional 15 minutes.
Let cool slightly before serving. Garnish with freshly grated parmesan and fresh parsley if desired and enjoy!