Grease or line an 8-inch square pan with parchment paper. Place the Nilla wafers in a food processor and pulse until they are broken down into fine crumbs (about 1 ½ cups or 180 g of crumbs from approximately 50 cookies). Add the light brown sugar and melted butter, then pulse until everything is well combined (3 tablespoons of light brown sugar and 6 tablespoons of melted unsalted butter). Transfer the crumb mixture into the prepared pan. Use the bottom of a measuring cup to press the crumbs evenly into the bottom of the pan. Freeze the crust for 20 minutes or refrigerate for 30-40 minutes while you prepare the cheesecake filling.

In a large bowl, beat the cream cheese and sugar together with a hand or stand mixer on medium speed until smooth and creamy, about 2 minutes. Scrape down the bowl to ensure all the cream cheese is blended (16 ounces of cream cheese and ½ cup or 100 g of granulated sugar). Beat in the sour cream and vanilla extract until just combined (¼ cup or 57 g of sour cream and 1 teaspoon of vanilla extract). In a separate small bowl or measuring cup, stir together the heavy cream and banana pudding mix until the pudding dissolves. The mixture will be thick (1 cup or 240 ml of heavy whipping cream and 3.4 ounces of banana pudding mix). Gradually beat in the heavy cream mixture in three additions, mixing thoroughly into the cream cheese mixture after each addition.

Pour the cheesecake filling over the chilled cookie crust and smooth out the top. Cover with plastic wrap and refrigerate for at least 8 hours or overnight to allow it to set. Once set, slice and serve. Top each slice with sliced banana, a dollop of whipped cream, and a Nilla wafer before serving.