01 - Preheat oven to 350°F. Grease a 9x13-inch baking dish lightly with butter or cooking spray.
02 - In a medium bowl, beat cream cheese with sugar until completely smooth. Add egg and vanilla extract, mixing until fully incorporated and creamy. Spread evenly in the bottom of the prepared baking dish.
03 - Arrange sliced bananas evenly over the cheesecake layer in a single layer.
04 - In a clean bowl, whisk together banana pudding mix and cold milk for 2 minutes until thickened. Pour over the banana layer and gently spread to cover evenly.
05 - Sprinkle crushed vanilla wafers evenly over the pudding layer.
06 - Evenly sprinkle the dry yellow cake mix over the top. 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, or until the top is golden brown and the center is mostly set. Cool for at least 30 minutes before serving.
09 - While cake cools, whip heavy cream with powdered sugar and vanilla extract until soft peaks form.
10 - Serve the dump cake warm or chilled, topped with freshly whipped cream. Garnish with additional banana slices and vanilla wafers if desired.