Preheat your oven to 375°F (190°C).
Prepare the zucchini by slicing them into thin rounds and placing them in a large bowl.
Add the cottage cheese, beaten eggs, garlic powder, salt, and pepper to the bowl with zucchini.
Stir in half of the cheddar cheese and the Parmesan cheese, mixing everything thoroughly.
Transfer the mixture into a greased baking dish and spread evenly.
Sprinkle the remaining cheddar cheese and breadcrumbs (if using) on top of the casserole.
Bake in the preheated oven for 35-45 minutes, until the cheese is bubbly and golden brown.
Remove from the oven and let it sit for about 10 minutes before serving.