Preheat your oven to 375°F (190°C) and line a baking sheet with parchment paper.
Cut the sourdough bread into cubes.
Melt the butter in a small saucepan or microwave-safe bowl, then stir in the garlic powder and salt.
Toss the bread cubes in the butter mixture until evenly coated.
Spread the cubes in a single layer on the baking sheet.
Bake for 12–15 minutes, stirring once halfway through, until golden brown and crispy.
Cool completely before storing in an airtight container.