1. Preheat the oven to 350°F. Spray two baking trays with cooking spray. Remove the center rib and stems from each kale leaf and discard. Tear or cut the leaves into bite-size pieces, about 2 to 3 inches wide. Wash the kale and dry it very well.
2. Place the kale in a large bowl. Drizzle with the oil and sprinkle with the garlic powder and salt, and massage the oil and seasonings into the kale with your hands to distribute evenly. Place the kale in a single layer on the baking sheets, and bake until crisp and the edges are slightly browned, 12 to 15 minutes.