In a large skillet, heat olive oil over medium heat. Add the chopped onion and minced garlic, sautéing until the onion is translucent, about 3-4 minutes.
Add the ground turkey to the skillet, and break it apart with a spatula. Cook until browned and cooked through, around 5-7 minutes.
Stir in the diced zucchini, cherry tomatoes, oregano, basil, salt, and pepper. Cook for an additional 5 minutes until the zucchini is slightly softened.
Remove the skillet from the heat and stir in the ricotta cheese until well combined.
In a greased 9x13 inch casserole dish, layer half of the turkey and vegetable mixture. Sprinkle half of the mozzarella cheese over it.
Pour the remaining turkey mixture on top and finish with the remaining mozzarella cheese. Sprinkle the grated Parmesan cheese over the top for added flavor.
Cover with aluminum foil and bake in the preheated oven for 20 minutes.
Remove the foil and bake for an additional 10-15 minutes, or until the cheese is golden and bubbly.
Let the casserole cool for a few minutes before slicing and serving.
Notes
Serve hot, garnished with fresh basil leaves and a sprinkle of extra Parmesan on top. Place in vibrant bowl for added color.