Set your oven to preheat at 250°F. This low temperature will help thoroughly dry out the focaccia croutons without burning them. Taking time to preheat ensures an even baking environment.

Place the cubed day-old focaccia in a large mixing bowl. Drizzle with olive oil or spray with olive oil spray. Add the dried oregano, dried basil, dried rosemary, and kosher salt. Toss and stir everything together until all the bread cubes are evenly coated with oil and seasoning. I like to use my hands to gently toss the cubes for more even coverage.

Spread the seasoned focaccia cubes in a single, even layer on a shallow, rimmed sheet pan. Make sure the cubes aren’t crowded; they need some space to dry out properly. Place the pan in the preheated oven. Bake, stirring or shaking the pan every 15-20 minutes to ensure even drying. This process will take between 45 minutes and 2 hours, depending on the starting moisture level of your bread and how much oil it absorbed.

To check if the croutons are done, take one out and let it cool for a moment, then bite into it. The crouton should be completely dry and crispy in the center. Once all the croutons are ready, let them cool completely on the pan before transferring to an airtight container for storage. I find they stay perfectly crunchy for up to 2-3 weeks.