Preheat the oven to 225 degrees F.
In a saucepan over medium-low heat, melt the butter. Remove from the heat ad stir in the garlic granules, basil, salt and cayenne.
Put the bread cubes in a large mixing bowl. Add the seasoned butter and quickly toss to coat the cubes evenly. Spread the buttered cubes on a baking sheet and bake until they are golden brown on the outside and crisp throughout, about 1 hour. (To test for doneness, cut or carefully bite into one of the larger croutons; its center should be completely dry and crisp.)
Store in an airtight container for up to 5 days.
Yield: 1 quart