1-Preheat oven to 375 degrees F: Preheat oven to 375 degrees F. Meanwhile, fit food processor with the steel blade attachment. Turn on motor and drop garlic through feed tube to mince. Remove lid and tear bread into three or four pieces each and add to the bowl of the food processor. Cover and process until the bread forms coarse crumbs. With the motor running, drizzle in olive oil.
2-Toss ¾ cup (about half) of the: Toss ¾ cup (about half) of the breadcrumbs, squash, tomato, basil, salt and pepper in a large bowl to combine.
3-Coat a 9 by 13 inch (or: Coat a 9 by 13 inch (or similar volume) casserole dish with cooking spray. Spread half of the squash mixture in the casserole dish. Top with half of the Italian cheese blend. Add the remaining squash and cover the casserole with foil. Bake until the squash is fork tender, about 50 to 55 minutes.
4-Increase oven temperature to 450 degrees F: Increase oven temperature to 450 degrees F. Remove foil, top with the remaining Italian cheese blend, Parmesan and the remaining breadcrumbs. Bake uncovered until the cheese is melted and the topping is golden brown, 12 to 15 minutes.