Preheat oven to 375°F (190°C). Line a baking sheet with parchment paper.

In a small saucepan, melt the butter over medium heat. Cook until it foams and turns golden brown with a nutty aroma, 3–5 minutes. Remove from heat and whisk in olive oil, garlic powder, thyme, salt, and pepper.

Place bread cubes in a large mixing bowl. Drizzle with the butter mixture and toss until evenly coated.

Spread bread cubes on the prepared baking sheet in a single layer.

Bake 12–15 minutes, tossing halfway through, until golden brown and crisp.

Cool slightly before serving — they will crisp more as they cool.