Preheat your oven to 350°F (175°C) and lightly grease an 8-inch baking dish with olive oil.

Bring a large pot of salted water to a boil, add the penne pasta, and cook according to package instructions (10-12 minutes). Drain and set aside.

In a skillet over medium-high heat, add olive oil and heat it up. Add minced garlic and sliced zucchini, sauté for about 10 minutes until zucchini is tender.

In the greased baking dish, combine cooked penne pasta, sautéed zucchini, spaghetti sauce, salt, black pepper, and chopped parsley. Mix well.

Sprinkle shredded mozzarella cheese generously over the pasta mixture.

Cover with aluminum foil and bake for 20 minutes. Remove foil and bake for an additional 10 minutes until cheese is golden and bubbling.

Let it cool for a few minutes before serving.