Whisk together pudding and milk. Refrigerate until set.
Meanwhile, cube pound cake. Reserve about 1/4 cup sliced bananas for top.
In a trifle bowl or similar start layers the trifle in the following order: 1/2 of the cubed pound cake, 1-2 cups Nilla wafers, 1/2 of the sliced bananas, 1/2 of the pudding mix, and half of the cool whip.
Next layer - on top of cool whip add remaining sliced bananas, remaining cubed pound cake, 1-2 cups Nilla wafers, remaining pudding, and top with cool whip.
Garnish with reserved sliced bananas, and a couple Nilla wafers,
Refrigerate until ready to serve.
Can be made 1 day ahead of time.
Ideas for swaps -