Remove tips from chicken wings and reserve for stock if desired; separate wings at joint, if not already seperated.
In large bowl, mix together mustard, butter, salt and cayenne pepper. Add wings, tossing to coat.
In shallow dish, combine bread crumbs, Parmesan cheese and oregano. Press wings into crumb mixture to coat all over; arrange on rack on foil-lined rimmed baking sheet.
(Make-ahead: Cover and refrigerate for up to 4 hours.).
Roast in 400°F (200°C) oven, turning once, until crisp and juices run clear when wings are pierced, about 45 minutes. The wings are more crunchy if you bake them on a rack and let air flow all around instead of directly on the baking sheet.