Preheat broiler. Place chocolate in a small microwave-safe bowl. Microcook on 50 percent power (medium) for 1-1/2 minutes. Let stand for 5 minutes. Stir until smooth. Let cool for 10 minutes.
Line a baking sheet with foil; lightly coat with nonstick cooking spray.
Place butter and coconut each in a shallow dish; roll marshmallows in butter and then coconut. Thread berries and marshmallows on 6-inch skewers and place on prepared baking sheet. Sprinkle any remaining coconut atop marshmallows. Spoon chocolate onto half of the graham crackers and arrange on a platter.
Broil skewers 3 to 4 inches from heat for 1 to 1-1/2 minutes or until coconut is lightly browned and marshmallows are puffed, turning once halfway through broiling.
To serve, immediately top each chocolate-coated graham cracker with a skewer. Use remaining graham cracker to pull marshmallows and berries off skewers and form sandwiches. Makes 12 servings.