Preheat the oven to 375℉/190℃. Grease or spray a 13x9 (3 quart) baking dish with butter or oil. Set aside.
If you need to cook the quinoa, do so first. Combine 1 cup dry quinoa with 2 cups of water or broth in a saucepan. Bring to a boil, cover, and simmer for about 15 minutes until the water is absorbed.
In a large skillet, warm 1 tablespoon of the olive oil. Add the onion and carrot. Cook for about 5 minutes until they start to soften. Add the garlic, ground beef, and salt. Break up the beef with a spoon as it cooks. Cook for about 7 to 9 minutes, stirring occasionally, until the beef is cooked through and the veggies are tender. Remove from heat. Add additional salt and pepper to taste.
Transfer the cooked quinoa and veggie and beef mixture to the prepared casserole dish. Stir in all of the ricotta cheese, 1 cup of the mozzarella, and 2 cups of the marinara sauce.
In the same skillet that you used for the beef and veggies, warm the other tablespoon of olive oil. Add the zucchini and cook for 5 to 7 minutes, stirring occasionally, until softened.
Layer the cooked zucchini on top of the mixture in the dish. Pour the rest of the sauce on top. Sprinkle with the remaining mozzarella cheese.
Bake for 25 to 30 minutes until bubbly. If desired, you can flip the oven to the broil setting at the end and cook for 1 to 2 minutes to toast the cheese on top a little more.
Garnish with fresh basil, serve warm, and enjoy!
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