Preheat your oven to 325 degrees Fahrenheit. This is the perfect temperature for baking the cheesecake, ensuring it cooks evenly without cracking.
Prepare a 10-inch springform pan by spraying it lightly with cooking spray. This will help the cheesecake release easily once it's set.
Add the vanilla wafer cookies to a blender or food processor and pulse until they become fine crumbs. This will serve as the delightful crust for your cheesecake.
In a medium bowl, combine the 1 ½ cups crushed vanilla wafers, ¼ cup granulated sugar, melted ¼ cup unsalted butter, and a pinch of salt. Mix until it resembles damp sand.
Pour the crumb mixture into the prepared springform pan and press it evenly into the pan. You can use the bottom of a flat glass or a measuring cup to really get it packed in.
Bake the crust for 10 minutes. Once done, allow it to cool completely while keeping the oven on, as the cheesecake will bake at the same temperature.
In the mixing bowl of a stand mixer, add the softened 32 ounces cream cheese and beat at medium/high speed for about 1 minute. Scrape down the sides and bottom of the bowl and beat for a few more seconds until smooth.
Add the 1 very ripe mashed banana and 4 ounces sour cream to the cream cheese. Mix at medium/low speed until just combined.
Scrape the bowl again and mix for another 30 seconds. Then, add in 1 cup granulated sugar and 1 (3.4-ounce) package of instant banana pudding. Mix until thoroughly combined.
Add 4 large eggs, one at a time, mixing on low speed until each egg is fully incorporated. This is crucial for a smooth cheesecake texture.
Stir in 1 tablespoon vanilla extract and mix until just combined.
Take a sheet of 18-inch heavy-duty aluminum foil and wrap it around the outside of the springform pan. Make sure the sheets are long enough to go up all sides to prevent water from getting into the pan during the water bath.
Place the wrapped pan in a deep roasting pan. Alternatively, you can use a baking sheet, as long as the sides are about 2 inches deep.
Add the cheesecake batter to the springform pan and smooth the top with a spatula.
Pour very hot water into the baking pan until about 1 ½ inches of water surrounds the springform pan. The water bath helps cook the cheesecake gently, preventing cracks.
Carefully move the baking pan to a rack positioned in the lower third of the oven. Bake for 1 to 1 ½ hours. After about an hour, check for doneness. The cheesecake should jiggle slightly but not be liquid. If it appears too liquid, give it an additional 15 minutes.
Once the cheesecake is firm with a slight wobble, turn off the oven and leave it inside for another hour. This gradual cooling prevents it from cracking.
After an hour, remove the cheesecake from the oven, carefully take off the foil, and chill in the fridge for 4 to 6 hours or overnight.
Prepare the second (3.4-ounce box) instant banana pudding according to the package directions and refrigerate until ready to serve.
Before serving, top the cheesecake with banana pudding, whipped cream, sliced bananas, and vanilla wafers. Enjoy your masterpiece!