Preheat the oven. Preheat your oven to 375°F (190°C) with the rack positioned in the center.
Make the bread cubes. Just slice into 3/4 inch wide slices from top to bottom, but don’t go all the way to the end. Then turn the loaf and do the same thing going lengthwise. Then, turn it over and cut it normally. Instead of slices, you’ll get cubes!
Prepare the seasoning mixture. In a small mixing bowl, combine the olive oil, dried basil, parsley, garlic powder, salt, and black pepper. Stir well to make sure the ingredients are evenly mixed.
Coat the bread cubes. Place the cubed sourdough bread into a large mixing bowl. Then, pour the olive oil and seasoning mixture over the bread cubes. Toss everything together with a wooden spoon or spatula until all the cubes are evenly coated.
Arrange on the baking sheet. Transfer the coated bread cubes to a parchment-lined baking sheet. Then, spread them out in a single layer, making sure they’re not overcrowded.
Bake. Place the baking sheet in the preheated oven and bake for 18-24 minutes or until the croutons are golden brown. Be sure to turn the croutons halfway through the baking time to make syure even browning. Remember that the baking time may vary depending on the size of your cubes, with sourdough generally taking a bit longer to turn golden compared to other bread types.
Cool and store. Once baked, remove the croutons from the oven and let them cool completely before serving. Store any leftovers in an airtight container at room temperature for up to 1 week, or freeze them for up to 1 month.