Make the spicy ranch. Whisk together buttermilk with sour cream, mayonnaise, hot sauce, dill, parsley, garlic powder, salt, black pepper, and onion powder. Set aside.
Combine almonds and cashews in a food processor and pulse until nuts become small crumbs. Add panko and pulse until well combined. Place panko mixture in one bowl, flour in another bowl, and whisk 2 eggs in another bowl.
Season chicken tenders with sumac, salt, and pepper. Dredge chicken in flour, shaking off the excess. Dip in the eggs and coat in the panko mixture.
Heat oil in a large saute pan over medium heat. Add the chicken tenders and cook until golden brown, about 3-4 minutes. Flip the chicken over, reduce heat to medium-low, and cook until the chicken is done. Remove from heat and serve with spicy ranch.
Notes
The spicy ranch can be prepared up to 5 days in advance.