Preheat oven to 400°F. Line a rimmed baking sheet with foil and set a wire rack on top.
Stir together brown sugar, smoked paprika, garlic powder, onion powder, salt, pepper, and cayenne in a small bowl.
Pat chicken dry. Trim and halve any large breasts so pieces are similar in size.
Toss chicken with olive oil and about half of the sugar-spice mix to lightly coat.
Wrap each chicken piece with a strip of bacon, tucking the end underneath. Place seam-side down on the rack.
Mix the remaining sugar-spice blend with melted butter to make a paste. Brush or pat it over the bacon-wrapped chicken.
Bake until chicken is 165°F and bacon is browned, 22–28 minutes depending on thickness.
Broil 1–3 minutes to crisp the bacon, watching closely. Rest 5 minutes.
Sprinkle with parsley and serve warm.