Preheat the oven to 400 degrees, and spray a large baking sheet with nonstick cooking spray.
In a shallow bowl, whisk together the buttermilk and garlic powder. In another shallow bowl, combine the bread crumbs, cheese, salt and pepper.
Cut the chicken into nugget size pieces, the dip each piece in the buttermilk mixture, then coat it well in the bread crumb mixture, and put it on the baking sheet.
Bake the nuggets for 15 – 20 minutes until they are just cooked through and very lightly browned, flipping once after about 10 minutes.
Serve them immediately, or refrigerate them for up to 3 days, or freeze them for up to 3 months.