Line a baking sheet with parchment paper, set aside.
Cut the loaf of crusty bread into 1" cubes.
Place the bread cubes in a large mixing bowl.
Top the bread cubes with olive oil and melted unsalted butter. Using a spatula, stir to combine.
Season the bread cubes by sprinkling the garlic powder, salt, pepper, and Italian seasoning over top.
Using your spatula, stir to fully combine. **You want to make sure all of the bread cubes are coated with the oil mixture and the seasoning.
Turn the prepared bread cubes on the parchment-lined baking sheet. Spread them out so they are evenly distributed on the baking sheet. **Overcrowding can result in your croutons not crisping up fully. If you have too many, work in batches or use another baking sheet.
Place the prepared bread cubes in the oven and bake at 350 degrees F (or 177 degrees C) for 8 minutes.
After the 8 minutes is done, flip the croutons over and bake for 6 more minutes.
Allow to cool for 10 minutes before serving. Allow them to cool completely if you plan on storing them immediately.
Notes
I recommend using a crusty-style loaf of bread in this recipe. They tend to crisp up nicely in the oven.I used unsalted butter in this recipe, if using salted butter or margarine reduce the salt slightly.