Trim off any fat from the chicken and then cut into 2-inch chunks. Place the chicken into a large mixing bowl or large storage bag.
In a small mixing bowl or measuring cup, whisk together the buttermilk, salt, pepper, and garlic powder. Pour this mixture over the chicken and toss to coat. Seal the bag or cover the bowl with plastic wrap, and refrigerate for a minimum of 30 minutes or up to 12 hours.
Once the chicken has been marinated, preheat the oven to 425℉. Spray a baking sheet lined with a baking rack with nonstick spray and set it to the side.
Combine the flour, panko, garlic powder, onion powder, salt, and paprika in a small shallow dish.
Remove the chicken from the buttermilk, shake off excess liquid, dip each chicken piece into the flour mixture, toss to coat, shake off excess flour, and place the coated chicken onto a baking rack that is on top of a baking sheet. Spray the chicken lightly with cooking spray.
Bake for 10-12 minutes, or until chicken is browned and cooked to 165℉. There is no need to flip the chicken, as the heat will circulate around the baking rack, ensuring each side gets crispy.
After the chicken is baked, allow it to cool slightly, and then brush the baked boneless wings with the sauce of your choice. Alternatively, you can toss the "wings" with the sauce in a large bowl.
Serve immediately.