Preheat the oven to 400°F. Line a baking sheet with parchment paper.
In a shallow bowl, combine crushed pretzels, garlic powder, paprika, salt, and pepper.
In another bowl, place the flour.
In a third bowl, beat the eggs.
Coat each chicken breast in flour, shaking off the excess.
Dip the chicken into the beaten eggs, then press into the pretzel mixture until well coated.
Place the coated chicken on the prepared baking sheet.
Drizzle the olive oil over the chicken.
Bake for 20-25 minutes, or until the chicken is cooked through and the coating is golden brown.
While the chicken is baking, prepare the mustard cheddar sauce by melting butter in a saucepan over medium heat.
Whisk in the flour and cook for 1 minute.
Gradually add the milk, whisking constantly until the mixture thickens.
Remove from heat and stir in the cheddar cheese and Dijon mustard until smooth. Season with salt and pepper to taste.
Serve the pretzel-crusted chicken hot, drizzled with mustard cheddar sauce.