In a large bowl, combine buttermilk, garlic powder, onion powder, paprika, salt, and black pepper. Add the chicken tenders to the marinade, ensuring they are fully coated. Cover and refrigerate for at least 1 hour, or up to overnight for best flavor.

In a shallow dish, mix together the flour and panko breadcrumbs. Stir in the shredded cheddar cheese.

Remove the chicken tenders from the marinade, allowing excess to drip off. Dredge each tender in the flour mixture, pressing gently to adhere. Set aside on a plate.

In a large skillet, heat about ½ inch of vegetable oil over medium-high heat. Once hot, carefully add the chicken tenders in batches, making sure not to overcrowd the pan. Fry for 4-5 minutes on each side or until golden brown and cooked through. Use a meat thermometer to ensure the internal temperature reaches 165°F.

Remove the tenders from the skillet and place them on a paper towel-lined plate to drain excess oil. Serve warm with ranch dressing for dipping.