Preheat oven to 400 degrees F. Line a large baking sheet with foil; lightly grease foil. Set pan aside.
In a shallow bowl whisk together egg, oil, 1/4 teaspoon salt, and cayenne pepper. Spread coconut in a second shallow bowl. Dip each chicken piece in egg mixture, allowing excess to drip off. Coat chicken with coconut. Arrange chicken on prepared baking sheet. Bake for 10 to 12 minutes or until chicken is no longer pink (170 degrees F).
Meanwhile, for salsa, in a medium bowl combine pineapple, mango, cilantro (if desired), lime juice, and 1/4 teaspoon salt. Serve with chicken.