Preheat the oven to 300ºF.
Place 1 kale leaf on a cutting board. Using a small, sharp knife, cut the middle vein and stem from the leaf and discard. Repeat for the remaining kale leaves.
Line 2 large baking sheets with aluminum foil and place a wire rack on top of each sheet. Evenly distribute the kale in one layer on each rack.
Coat the kale lightly with 4 seconds of olive oil spray, then carefully sprinkle salt and pepper over the kale.
Place in the oven and bake until crisp, about 15-20 minutes.