Pat chicken tenderloins dry with paper towels. Place them in a medium bowl and pour buttermilk over them, ensuring all pieces are coated. Let them sit at room temperature for 15 minutes, or refrigerate for up to 30 minutes.

Set up your dredging station: In a shallow bowl, combine flour, cornstarch, smoked paprika, garlic powder, onion powder, cayenne pepper (if using), salt, and black pepper. Whisk to combine. In a second shallow bowl, whisk the egg with 1 tablespoon of water. In a third shallow bowl, add the Panko breadcrumbs.

Working one at a time, remove a chicken tender from the buttermilk, letting excess drip off. Dredge in the flour mixture, shaking off any excess. Dip into the egg mixture, then press firmly into the Panko breadcrumbs, ensuring full coverage.

Preheat your air fryer to 375°F (190°C). Lightly spray the air fryer basket with vegetable oil spray. Place the breaded chicken tenders in a single layer in the basket, ensuring they are not overcrowded (you may need to cook in batches). Lightly spray the tops of the tenders with oil spray.

Air fry for 10-12 minutes, flipping halfway through, until golden brown, crispy, and cooked through (internal temperature reaches 165°F / 74°C). Repeat with remaining chicken.

While the chicken cooks, prepare the honey mustard sauce: In a small mixing bowl, whisk together mayonnaise, Dijon mustard, honey, apple cider vinegar, and cayenne pepper (if using) until smooth. Taste and adjust seasonings as needed.

Cook the bacon until crispy. Once cooked, transfer to a paper towel-lined plate to drain excess grease. Crumble into small pieces once cool enough to handle.

Lightly toast the brioche hot dog buns. This can be done in a dry skillet over medium heat for 1-2 minutes per side, in a toaster, or in the air fryer for 1-2 minutes until warm and lightly golden.

To assemble each Bird Dog Sandwich, place one or two crispy chicken tenders into a toasted hot dog bun. Drizzle generously with the homemade honey mustard sauce. Top with shredded cheddar cheese and a sprinkle of crispy crumbled bacon.

Serve immediately, optionally with dill pickle chips on the side or tucked into the bun.