Heat oven to 300°F. Trim crusts from bread; cut slices into 1/2-inch cubes. Spread cubes in ungreased 15x10x1-inch baking pan. Drizzle butter over cubes; toss to coat.
Bake at 300°F. for 30 to 35 minutes or until dry, crisp and golden brown, stirring occasionally. Store covered in refrigerator.