In a large bowl, combine buttermilk, garlic powder, onion powder, paprika, salt, black pepper, and cayenne pepper (if using). Add the chicken tenderloins and ensure they are fully submerged. Cover and refrigerate for at least 1 hour, or up to overnight for better flavor.

In a shallow dish, mix together the flour and a pinch of salt. In another shallow dish, place the breadcrumbs.

Remove the chicken from the buttermilk marinade, allowing excess to drip off. Dredge each tenderloin in the flour mixture, shaking off any excess, then dip it back into the buttermilk, and finally coat it in the breadcrumbs, pressing gently to adhere.

In a large skillet, heat about 1 inch of vegetable oil over medium-high heat until it reaches 350°F. Carefully add the chicken tenders in batches, making sure not to overcrowd the pan. Fry for about 4-5 minutes on each side or until golden brown and cooked through.

Use a slotted spoon to transfer the cooked tenders to a paper towel-lined plate to drain excess oil.

Serve hot with your favorite dipping sauces.