Preheat the oven to 400°F (200°C). Line a baking sheet with aluminum foil and lightly coat with cooking spray; set aside.
In a large shallow bowl, combine the panko breadcrumbs, grated Parmesan, salt, and black pepper; stir to mix evenly and set aside.
Place the melted butter in a medium bowl. Dip each chicken piece into the butter, then press into the breadcrumb mixture to coat well; arrange coated pieces on the prepared baking sheet.
Sprinkle any remaining breadcrumb mixture over the coated chicken pieces to ensure even coverage.
Bake the nuggets for 30 to 33 minutes, until the chicken is cooked through and the coating is lightly golden; bottoms may brown more than tops. Adjust time as needed for piece size and oven variance.
While the chicken bakes, whisk together the honey, yellow mustard, and Dijon mustard in a medium bowl; taste and adjust sweetness or tang by adding more honey or mustard as desired.
Serve the baked chicken nuggets warm with the honey mustard dipping sauce.
