Heat oven to 350° F. Dividing evenly between 2 rimmed baking sheets, toss the bread with the oil and 1½ teaspoons salt. Arrange in a single layer and bake, tossing the bread and rotating the pans halfway through, until golden and crisp, 25 to 30 minutes. Let cool completely on the pans.
Before baking, try tossing the bread with one of the following: Herbs: ¼ cup chopped fresh flat-leaf parsley and 1 tablespoon chopped fresh thyme or rosemary.Spices: 2 tablespoons paprika, 1 teaspoon ground cumin, and ½ teaspoon cayenne pepper.Cheese: ¾ cup grated Parmesan. (Use cheese croutons within 1 week.)