3 medium zucchini, sliced
2 medium onions, sliced
2 Tbsp. olive oil
Salt and pepper to taste
16 oz. uncooked penne pasta
28 oz. jar marinara sauce
½ c. Parmesan cheese, grated
Preheat oven to 400°. Toss zucchini and onions in a large bowl with olive oil until evenly coated. Spread vegetables into a large baking dish. Roast in the preheated oven until golden, about 30 minutes. Remove from oven and season with salt and pepper.
Reduce oven temperature to 350°. When the vegetables are almost finished roasting, bring a large pot of lightly salted water to a boil. Add pasta and cook, stirring occasionally, until tender yet firm to the bite, about 10 minutes; drain.
Lightly grease a 9x13 baking dish. Heat marinara sauce in a saucepan over medium heat until hot. Spread sauce into the prepared baking dish. Top with cooked pasta, followed by roasted zucchini and onions. Sprinkle with Parmesan cheese. Bake 35-40 minutes. Remove from oven and let rest for a few minutes before serving.