In a large bowl or resealable plastic bag, combine the chicken, dill pickle juice, brown sugar, and 2 teaspoons kosher salt. Refrigerate and marinate for 1 to 24 hours.
When ready to cook, preheat the oven to 425°F (220°C). Spread the panko crumbs in an even layer on a baking sheet and toast in the oven 5–7 minutes until golden, watching carefully so they do not burn. Transfer toasted panko to a shallow bowl and line the baking sheet with parchment paper.
In a shallow bowl, mix the flour, 1 teaspoon salt, garlic powder, and chili powder.
In a second shallow bowl, whisk the eggs with 2 tablespoons water until combined.
Remove a piece of chicken from the marinade, letting excess drip off. Dredge the chicken in the seasoned flour, then dip into the egg mixture, and finally press into the toasted panko to coat thoroughly. Place coated tenders on the prepared baking sheet.
Bake the chicken at 425°F for 18–25 minutes, until the coating is golden and the internal temperature reaches 165°F (74°C).
Serve the hot chicken immediately with extra pickles and optional sauce.