Rinse the chickpeas and spread them on a paper towel to dry out for an hour or so. Blot them with another paper towel as they dry.
Arrange an oven rack in the middle position and preheat the oven to 400℉. Line a heavy-rimmed sheet pan with parchment paper. Scatter the chickpeas evenly on the pan. Remove and discard any chickpea skins that became loose.
Bake for about 30 minutes. Taste a chickpea. If it is crunchy, they’re done. If not, continue baking another 5 minutes or so, until crispy.
Transfer the hot chickpeas to a bowl. Drizzle with olive oil, za'atar or other spices, and salt (if using).