1Cut chicken tenders to even sizes and submerge in 1 carton of buttermilk in a sealed bowl or bag. Refrigerate for 1 hour or overnight.
2Mix 1.5 cups flour, 1 tsp garlic powder, 1 tsp paprika, 1/2 tsp cayenne, 1 tsp salt, and 1/2 tsp black pepper in a shallow dish.
3Remove chicken from buttermilk, letting excess drip off, then dredge in flour mixture, shaking off excess.
4Heat oil to 170c in a fryer or pot. Fry chicken pieces without crowding, 3-4 minutes each side, until internal temperature reaches 75c.
5Drain cooked chicken on a wire rack or paper towel-lined plate.
6For the sauce, combine 1/2 cup mayonnaise, 1/4 cup ketchup, 1/2 tsp garlic powder, 1/2 tsp Worcestershire sauce, and 1/4 tsp black pepper. Whisk until smooth.