Measure 3 cups mashed bananas, lemon juice, sugar and cinnamon, and add to a large saucepan. Mix well. Bring to a rolling boil, and boil for 1 minute, stirring constantly. Remove from heat, and stir in the pectin. Mix well. Pour into clean, hot sterilized jars, and seal. Process in a boiling-water bath for 10 minutes. Optional: Can add 1/4 cup chopped golden raisins and/or 1/4 cup chopped maraschino cherries when you add the pectin.