In a large plastic bag, put in your chicken, buttermilk, and salt. Tightly seal and give it a good swish to make sure the chicken is coated. Let sit in refrigerator for at least 4-6 hours or up to 24 hours.
Heat oven to 375˚ F. Line a baking sheet with parchment paper or use a baking rack.
Prepare three separate plates. (Whisk flour with spices on first plate)
Take buttermilk soaked chicken out of bags, gently shaking off any excess buttermilk. Dip chicken in flour mixture first, then egg mixture, then firmly press breadcrumbs all over chicken until chicken is completely covered. Place on baking sheet.
Bake chicken tenders for 18-20 minutes or until chicken is cooked through. Place chicken under broiler for last 1-2 minutes to brown and crisp up.
Meanwhile, make your honey mustard by whisking together mustard, honey, and salt and pepper. Serve chicken fingers warm or at room temperature with honey mustard sauce.
These chicken fingers are best eaten when they come out of the oven, but they are also delicious 2-3 days later (they just don't retain as much of their crispiness). To reheat: I highly recommend putting them back in the oven at 350˚ for 15-20 minutes before eating as opposed to placing in the microwave.