Preheat the oven to 400°F. Line a baking sheet with foil. Spray a 9x13-inch baking dish with non-stick cooking spray.

In a medium bowl, toss the zucchini slices with olive oil. Transfer the zucchini to the prepared baking sheet, arranging the slices in an even layer. Season to taste with salt and pepper. Roast for 10 minutes, until tender.

Cook the pasta according to package directions. Drain and return to the pot; set aside.

Into a medium saucepan over medium heat, add the remaining 1 teaspoon of olive oil. When the oil is hot, add the onion and Italian seasoning. Cook for 2 minutes, until softened. Add the garlic and continue cooking for an additional 30 seconds. Stir in the marinara sauce and adjust seasoning to taste.

Pour the marinara sauce over the cooked pasta and stir to coat. Transfer to the prepared baking dish.

Spread the roasted zucchini over the pasta. Sprinkle with mozzarella and parmesan cheeses.

Bake for 20 minutes, until cheeses are melted. Serve hot.