Marinate the chicken tenders in a mixture of buttermilk, garlic powder, onion powder, paprika, black pepper, and salt for at least 1 hour or overnight.
Prepare the ranch coating by mixing all-purpose flour with ranch seasoning in one dish and placing panko breadcrumbs in another.
Bread the chicken tenders by dredging them in the flour mixture, dipping them back in buttermilk, and then coating with panko breadcrumbs.
Preheat the oven to 400°F and bake the chicken tenders for 20-25 minutes, flipping halfway through until golden brown.