Preheat oven to 400°F (200°C) and line a baking sheet with parchment paper.
Process pretzels in a food processor until they reach a coarse sand consistency; transfer to a shallow bowl.
Place flour in a separate shallow dish.
Whisk eggs and Dijon mustard together in a third shallow dish.
Season chicken tenders with garlic powder and black pepper.
Dredge each chicken piece in flour, shaking off excess, then dip into the egg mixture until fully coated.
Press the chicken firmly into the pretzel crumbs to ensure an even and thick coating.
Arrange chicken fingers on the prepared baking sheet and lightly mist with cooking spray.
Bake for 12 to 15 minutes, flipping once at the 7-minute mark, until internal temperature reaches 165°F (74°C).