Peel shrimp, leaving the tails intact. Starting at tail end, butterfly each shrimp, cutting to, but not through, underside of shrimp.
Combine shrimp, 6 tablespoons of Honeyed Lemon-Dijon Vinaigrette, and red pepper in a large zip-top plastic bag. Seal and marinate in refrigerator 15 minutes, turning bag occasionally.
Prepare grill to medium-high heat.
Remove shrimp from marinade; discard marinade.
Sprinkle shrimp evenly with salt and black pepper.
Place the shrimp, cut sides down, on grill rack coated with cooking spray; grill 2 minutes on each side or until done, basting frequently with the remaining 6 tablespoons of Honeyed Lemon-Dijon Vinaigrette.