Preheat oven to 300F and line a baking sheet with parchment paper.
Add the bread cubes to a medium-sized bowl. Slowly drizzle on the oil, making sure to cover as much of the bread as possible.
Sprinkle on the seasonings and gently toss to combine, pressing the seasonings into the bread cubes as you toss.
Arrange the bread in a single layer on the prepared baking sheet. Sprinkle on any remaining crumbs from the bowl and press them into the bread cubes.
Bake for 25-30 minutes, or until golden brown and crunchy. (If they start to brown too much on one side, flip them over).
Remove from the oven and let cool on the baking sheet for 2 hours before transferring to an airtight container. They will get crunchier as they cool.
Notes
Stale bread. Make sure your bread is stale. And not just a day old. It should be a few days old. Stale bread is the key to making extra crunchy croutons.
Spray oil. If you'd like more even coverage of oil on the croutons, try using an olive oil spray.
Gently toss and press the seasoning into the cubed bread. If you're too rough or toss them too much, the bread may start to crumble.
Bake until golden and crispy. You don't want the croutons too toasty, but you want them golden brown and crispy. Flip them over if one side is browning too much.
Let cool completely. I normally let the croutons cool on the pan for 1-2 hours before storing them just to make sure they're fully cooled and crunchy.