One small box will be enough.
I have found that a chopstick or the end of a wooden spoon works best for poking holes.
While cool whip works good in a pinch... if you want "to die for" whipped frosting use one packet of dream whip with one package lemon pudding and 1 1/2 cups of milk - beat until fluffy.
I've also done lemon cake with raspberry jello and lemon frosting. Yummy!
...we need to quit talking about jello cake, making me hungry.
