Combine the first 5 ingredients in a bowl, and stir with a whisk. Peel the shrimp, leaving tails intact. Add the shrimp to maple mixture, tossing to coat. Remove shrimp from bowl, and discard the marinade. Cut each prosciutto slice lengthwise into 4 strips. Wrap 1 prosciutto strip around each shrimp. Thread shrimp onto 4 (8-inch) skewers. Place skewers on a broiler pan coated with cooking spray, and broil for 3 minutes on each side or until done. Serve shrimp over Lemon Couscous.