Break graham crackers in half. Break chocolate bar in half; center one section on each of 2 graham cracker halves. Top each with marshmallow. Place on paper towel. Microwave at MEDIUM (50%) in 10 second intervals until marshmallow puffs. Top each with another graham cracker half; press gently. Let stand 1 minute to soften chocolate. Serve immediately. 2 snacks.
CONVENTIONAL METHOD: Center half of chocolate bar on each of 2 graham cracker halves. Place remaining 2 graham cracker halves on cookie sheet; top each with marshmallow. On middle oven rack, broil 30 seconds or just until marshmallows are golden brown. Immediately invert onto chocolate-topped graham crackers; press gently. Let stand 1 minute to soften chocolate. Serve immediately.
PEANUTTY VARIATION: Spread thin layer REESE'S Creamy or Crunchy Peanut Butter on graham crackers. Proceed as directed.
CHOCOLATE BANANA S'MORE: Place slices of banana on top of chocolate bar; proceed as above.
CHOCO-CHERRY S'MORE: Cut two maraschino cherries into slices; place on top of chocolate bar; proceed as above.
CHOCO-BERRY S'MORE: Place slices of strawberries on top of chocolate bar; proceed as above.
RASPBERRY S'MORE: Spread thin layer of seedless red raspberry preserves on graham cracker.