One 4-ounce bar bittersweet chocolate, broken into 4 rectangles
12 large marshmallows
Preheat the oven to 350°. Spread the shredded coconut on a pie plate and toast for about 4 minutes, until golden. Arrange four 8-inch sheets of aluminum foil on a work surface. Place 1 graham cracker on each sheet and top with a piece of chocolate. Mound the coconut on top.
Thread 3 marshmallows on each of 4 skewers. Toast the marshmallows over a gas flame until golden and melted. Slide the marshmallows onto the coconut and top with the remaining graham crackers. Wrap the s'mores in the foil and bake for 3 to 4 minutes, until the chocolate is just melted. Serve.