In medium bowl, place 3/4 cup chocolate chips; set aside. In 1-quart saucepan, heat 1/3 cup whipping cream and 1 tablespoon butter over medium heat, stirring until butter is melted and mixture begins to boil. Pour cream mixture over chocolate in bowl; stir until smooth. Add crushed granola bars and marshmallows; mix well. Spoon slightly less than 1 measuring tablespoonful mixture into each muffin cup; gently press into cups.