Preheat oven to 350 degrees. Bring a large pot of salted water to a boil. Add pasta, and cook according to the package directions.
Add bread to a food processor and pulse until coarse crumbs form. Remove, and set aside. In a large heatproof skillet, heat 2 tablespoons oil over medium-high heat. Add garlic, and cook until fragrant, about 1 minute. Stir in breadcrumbs, and season with salt and pepper. Transfer skillet to oven, and bake until golden brown.
In another large skillet, heat remaining 1/3 cup oil over medium-high heat. Add zucchini, and butter. Cook until just beginning to turn golden brown.
Drain pasta, and transfer to a large shallow bowl. Sprinkle with parsley and Parmesan; toss to combine. Using a slotted spoon, transfer zucchini to pasta, adding as much of the oil as desired. Top with toasted breadcrumbs, and serve immediately.