Preheat the oven to 350 degrees F. Lightly grease a 9-by-13-inch baking dish with 1 teaspoon oil.
Bring a large pasta pot of water to a boil over high heat. Add a big pinch of salt and the pasta. Cover and return the water to a boil. Remove the cover and cook for 5 minutes. The pasta will not be completely cooked through.
Meanwhile, in a large skillet over medium-high heat, add 1 tablespoon oil. When it is hot, add the onions and zucchini and cook until they are softened and brown slightly, about 5 minutes. Add the garlic and pepperoni and cook for another minute. Add the tomatoes and basil and simmer for 5 minutes. Taste and adjust the seasoning with salt and pepper. Reserve 1 cup of the tomato sauce for another use, such as Round 2 Recipe Garlic Bread Pizza.
Stir in the pasta and cheese into the skillet. Pour into the prepared baking dish and smooth out the top. Sprinkle the breadcrumbs evenly over the top and drizzle with the 1 tablespoon oil. Bake until the top is browned and the casserole is bubbling, 20 to 25 minutes.