01 - Preheat oven to 350°F. Grease a 9x13-inch baking dish lightly with butter or cooking spray.
02 - Beat cream cheese and sugar in a medium bowl until smooth. Add egg and vanilla extract, mixing until fully combined and creamy. Spread evenly across the bottom of the prepared baking dish.
03 - Arrange sliced bananas in a single layer over the cheesecake mixture, ensuring even coverage.
04 - Whisk banana pudding mix and cold milk together for 2 minutes until thickened. Pour over the banana layer and spread gently to create an even surface.
05 - Sprinkle crushed vanilla wafers evenly over the pudding layer.
06 - Evenly distribute the dry yellow cake mix over the wafers. Do not stir or mix the layers.
07 - Drizzle melted butter over the cake mix, covering as much surface area as possible.
08 - Bake for 45–50 minutes until the top is golden brown and the center appears mostly set.
09 - While cake bakes, whip heavy cream with powdered sugar and vanilla extract until soft peaks form.
10 - Allow cake to cool for at least 30 minutes before serving. Serve warm or chilled, topped with whipped cream, fresh banana slices, and extra vanilla wafers if desired.