1. Prepare the Yellow Cake according to directions on the box. 2. Once cake is done, let cool for about 20 minutes. 3. Using the handle of a wooden spoon, poke holes in the cake. 4. Prepare the Banana Cream Pudding according to directions on the box. 5. As soon as the lumps of the pudding are gone, pour over cake before pudding has a chance to set and thicken. Focus on getting the pudding into the holes. 6. Cover and refrigerate for at least 30 minutes to let the pudding set. 7. Slice bananas and place them on top of the pudding. 8. Spread Cool Whip over the top of the cake. 9. Put 30 Vanilla Wafers in a zip lock bag and crush. The amount you crush them is completely up to, some like them crushed up fine and some like big chunks. I like a little of both! Sprinkle wafers on top of the Cool Whip and serve!.