Step 1

Preheat the oven to 350°F. In a large bowl, combine the cake mix, water, eggs and oil. Beat on low speed for 30 seconds. Increase the speed to medium and beat for another two minutes.

Step 2

Pour the batter into a greased 13x9-inch baking dish. Bake until a toothpick inserted in the center comes out clean, 25 to 35 minutes.

Step 3

Cool the cake in the pan for 15 minutes. Pierce the cake with the end of a wooden spoon in 1/2-inch intervals. Editor's Tip: You want the holes big enough for the pudding to seep into. Make sure they're wide, but don't put too many in the cake or it will become mushy.

Step 4

In a small bowl, combine the milk and pudding mix. Whisk for two minutes. Immediately spread the pudding over the top of the cake and into the holes. Editor's Tip: When spreading the pudding over the cake, gently push it into the holes so they are filled. The whole point of a poke cake is to have pudding inside the holes. Even out the layer with an offset spatula

Step 5

Refrigerate the cake for 30 minutes. Editor's Tip: Don't skip this step! The pudding mix must chill to thicken and set properly.

Step 6

Remove the cake from the fridge. Slather the defrosted whipped topping across the cake. Sprinkle the sliced bananas and crushed wafer cookies over the top.

Step 7

Cover the pan with storage wrap or foil. Refrigerate for at least one hour. Editor's Tip: Keep the cake in the refrigerator until you're ready to serve it.