Slice the loaf, including crust, into 1/2-inch to 1-inch cubes. For a rustic look, tear the bread by hand.
To dry bread cubes on the counter:
On a rimmed baking sheet, spread the bread cubes in a single layer and cover with a dry kitchen towel. Dry at room temperature for 2 to 3 days.
To dry bread cubes in the oven:
On a rimmed baking sheet, spread the bread cubes in a single layer. Bake until dry, about 30 to 40 minutes.
Notes
Bread: You can use almost any type of high-quality bread: unsliced French or Italian bread, sturdy sandwich loaf, brioche, challah, or even corn bread. Avoid overly-soft or fluffy white sandwich loaves.
Yield: A 1-pound bread loaf makes about 10 cups of bread cubes, enough for a 9-inch by 13-inch baking dish of stuffing, or 10 to 12 servings (assume 1 cup stuffing per person).