I used the 4 serving size boxes of pudding. I know they make 6 serving size, too. Those would also work, you would just have LOTS of pudding and need to put less cool whip on top. Enjoy!
INGREDIENTS
3 small (4 serving size) packages instant pudding Prepared as directed (6 cups)
8 oz cool whip thawed
1 Box graham crackers
INSTRUCTIONS


    Lay out graham crackers in a 9 x 13 pan
    Cover graham crackers with half of pudding
    Layer graham crackers over the pudding layer
    Cover graham cracker layer with remaining pudding
    Top with cool whip
    Refrigerate overnight or for at least 6 hours
    Cut & serve like cake