Preheat oven to 350°F and spray a 9×13 baking dish with cooking spray.
Cook the meat + veggies: Heat olive oil in a large skillet, then add the onion and zucchini. Season with ½ teaspoon salt, ½ teaspoon garlic powder, and oregano. Add the ground meat and cook, breaking apart, until browned (about 5–8 minutes). Remove from heat.
Start layering directly in the pan: Pour ¼ cup milk in the bottom of the pan. Add a layer of oven-ready noodles, breaking pieces so they cover the edges
First filling layer: Spread ⅓ of the marinara. Add 1 cup mozzarella. Add 3/4 container of cottage cheese. Sprinkle ¼ teaspoon garlic powder, oregano, and a pinch of salt
Second layer: Add another noodle layer. Spread ⅓ marinara. Add remaining cottage cheese. Add the meat/veggie mixture. Add 1 cup mozzarella
Final layer: Add noodles. Spread remaining marinara. Top with remaining 1–2 cups mozzarella cheese.
Bake: Cover tightly with foil and bake for 20 minutes, then uncover and bake 25–35 minutes, or until bubbly and browned on top.
Rest before slicing: Let sit for at least 5-10 minutes before cutting -this helps it set!