Preheat the oven to 275 degrees F. Line 2 baking sheets with parchment paper. Remove the thick stems from the kale and discard; tear the leaves into pieces. Lay on the prepared baking sheets and spray evenly with cooking spray. Bake, tossing the kale halfway through, until crispy, about 35 minutes.
Meanwhile, make the barbecue seasoning: Combine the paprika, chile powder, brown sugar, garlic powder, mustard powder and 1 1/2 teaspoons salt in a bowl. Remove the kale from the oven and sprinkle with some of the seasoning.
Photograph by David Malosh
Courtesy of Food Network Magazine