In a large bowl, add the chicken tenderloins and pour in the buttermilk, pickle juice, mustard, hot sauce, and seasonings. Mix well until the chicken is fully coated, then cover and marinate for at least 30 minutes (or up to overnight for best flavor).
In a separate bowl, combine the flour, cornstarch, and seasoning. Mix until evenly combined.
Remove the chicken from the marinade, letting excess drip off, then dredge each tender in the flour mixture. Press the coating onto the chicken to ensure it sticks well for that crispy texture.
Heat vegetable oil in a deep pan or skillet to 350°F. Carefully add the chicken tenders in batches, making sure not to overcrowd the pan.
Fry for about 4–6 minutes, flipping halfway through, until golden brown and fully cooked. Transfer to a wire rack or paper towel-lined plate.
In a bowl, mix together mayonnaise, sweet chili sauce, and sriracha until smooth and creamy.
Toss the fried chicken tenders in the bang bang sauce or drizzle it over the top, depending on your preference.
Garnish with parsley, serve hot, and enjoy!