If using whole chicken breasts, trim any fat and slice each breast into 3–4 even tender strips about 1 to 1 1/2 inches wide. Pat dry with paper towels.

Season the chicken pieces evenly with 1 tsp kosher salt, 1 tsp black pepper, 1 tsp garlic powder and 1 tsp smoked paprika. Place the seasoned pieces in a shallow dish or bowl.

Pour 1 cup buttermilk over the chicken so pieces are coated. Cover and refrigerate for at least 30 minutes and up to 4 hours. This tenderizes and adds moisture.

For the Breading

Set up a three-station breading area: 1) flour in a shallow bowl, 2) beaten eggs in another shallow bowl, 3) panko mixture in a third bowl.

In the bowl for panko, combine 1 cup panko breadcrumbs, 1/4 cup grated Parmesan (if using), 1/2 tsp onion powder, 1/4 tsp cayenne pepper, 1/2 tsp kosher salt and 1/2 tsp black pepper. Mix well.

Remove one piece of chicken from the buttermilk, letting excess drip off. Dredge first in flour, shaking off excess, then dip into beaten eggs, then press into the panko mixture so the exterior is well coated. Place breaded tenders on a wire rack. Repeat with remaining pieces. For an extra-crispy double-coat, repeat the egg and panko step once more.

Let the breaded tenders rest on the rack for 10–15 minutes at room temperature; this helps the breading adhere and promotes even frying.

For Frying / Finishing

Pour about 1 1/2–2 cups oil into a heavy skillet or Dutch oven (enough to come about 1/2 inch up the side) and heat over medium-high to 350°F (175°C). If you don't have a thermometer, test by dropping a small piece of breading into the oil — it should sizzle and brown in about 45–60 seconds.

Working in batches (do not overcrowd), carefully add breaded tenders to the hot oil. Fry 3–4 minutes per side, flipping once, until golden brown and the internal temperature of the thickest part reaches 165°F (74°C). Adjust heat as needed to maintain 325–350°F; if oil is too hot they will brown too quickly, too cool and they will absorb oil.

Use a slotted spoon or tongs to transfer cooked tenders to a wire rack set over a baking sheet to drain. Season lightly with a pinch of salt while still hot, if desired. Keep finished tenders warm in a 200°F (95°C) oven while frying remaining batches.

When all tenders are cooked, sprinkle with chopped fresh parsley and serve with lemon wedges and your choice of dipping sauce.