Preheat oven to 300 degrees.
Slice the bread into roughly 1-inch cubes. Spread them on a baking sheet. Bake at 300 degrees until hardened on the outside but still slightly soft in the middle, 15 to 20 minutes, stirring once or twice during baking.
Using a mandolin or sharp chef’s knife, cut squash into paper thin slices. Cut cherry tomatoes in half. Whisk together olive oil, red wine vinegar, garlic, salt and pepper. In a large salad bowl, toss together all the ingredients with basil leaves.