In a small bowl add the unflavored gelatin to the cold water. Lightly stir to mix and set aside.
In a small saucepan,, bring the pineapple juice to a boil. Remove from heat.
Add the gelatin mixture to the pineapple juice and stir until dissolved.
Pour pineapple juice mixture into a large mixing bowl and place in the freezer for about 20 minutes to cool down.
Cut the jello into 1 inch cubes (The easiest way to do this is to use a knife and cut lines across your dish in both directions about an inch apart. use a thin spatula to remove the cubes from the dishes.)
Put all the cubed jello into a large mixing bowl .
Remove pineapple mixture from the freezer. (Make sure it has cooled)
Add the cool whip to the juice and lightly fold in. ( It should be well mixed but only stir lightly, so as not to lose the fluffiness of the cool whip.)
Add the cool whip mixture to the cubed jello and fold in gently.
Pour over the graham crust and smooth the top with a spatula.
Sprinkle the reserved crumb mixture over the top.
Chill in the refrigerator for at least 3 hours or until firm.
Cut into two inch squares.