Step 1: Make the pudding. In a large mixing bowl, whisk together the vanilla instant pudding mix and 2 cups of cold milk until it thickens, which usually takes about 2 minutes.
Step 2: Add the whipped topping. Gently fold the entire 8 oz container of thawed whipped topping into the prepared pudding mixture until it's smooth and well combined.
Step 3: Layer the dessert. In your chosen serving dish (a 9x13 inch pan or individual parfait glasses work well), arrange a layer of Nilla wafers on the bottom. Follow this with a layer of sliced ripe bananas, then a generous layer of the pudding mixture, and finally a spoonful of strawberry pie filling or fresh chopped strawberries.
Step 4: Repeat layers. Continue layering the Nilla wafers, banana slices, pudding mixture, and strawberry until all ingredients are used. Make sure to finish with a final layer of the creamy pudding. For garnish, place a few extra Nilla wafers on top.
Step 5: Chill the pudding. Cover the serving dish tightly with plastic wrap and refrigerate for at least 2 hours. This allows the flavors to meld beautifully and the dessert to set perfectly.