In a large bowl, combine the buttermilk, garlic powder, onion powder, paprika, salt, black pepper, and cayenne pepper (if using). Add the chicken tenderloins and marinate for at least 30 minutes, or up to 2 hours in the refrigerator for better flavor and tenderness.

In a separate shallow dish, place the flour. In another shallow dish, add the breadcrumbs.

Remove the chicken from the marinade, allowing excess buttermilk to drip off. Dredge each tenderloin in flour, shaking off the excess, then dip it back into the buttermilk, and finally coat it in 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 breaded chicken tenders to the hot oil in batches, making sure not to overcrowd the pan. Fry for about 3-4 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 warm with your favorite dipping sauces.