Preheat the oven to 350°F and line a spacious baking sheet with parchment paper to prevent sticking and ensure even roasting.

Thoroughly rinse the chickpeas under cold running water in a colander until the water runs clear and no foam remains. Drain them well, then spread them out on a clean kitchen towel. Pat them dry by gently rubbing them with the towel, removing as much moisture as possible. Discard any loose skins that naturally separate during the drying process. Properly dried chickpeas will roast more evenly and achieve a crispier texture.

Transfer the chickpeas to a large mixing bowl. Drizzle the olive oil evenly over them, followed by the sumac, smoked paprika, garlic powder, sea salt, and black pepper. Use a large spoon or clean hands to toss everything together, ensuring each chickpea is well-coated in the flavorful seasoning blend.

Evenly spread the seasoned chickpeas in a single layer on the prepared baking sheet, avoiding overcrowding. Roast for 45 minutes, shaking the pan gently at the 15- and 30-minute marks to encourage even crisping. The chickpeas should feel dry and crunchy to the touch when done. Keep in mind that they will continue to crisp up as they cool.

Enjoy immediately for the best texture, or store them at room temperature in a jar or bowl, uncovered or lightly covered with a kitchen towel or paper towel, for up to three days.