Preheat your oven to 350°F (175°C). In a mixing bowl, combine graham cracker crumbs, white sugar, and melted butter until the mixture resembles wet sand. Press this mixture evenly into the bottom of a square pan to form a crust. Bake for 6 minutes, then set aside to cool completely.

In a separate bowl, whisk together 2 cups of cold milk and the instant banana pudding mix for about 2 minutes, ensuring no lumps remain. Incorporate softened cream cheese into the pudding mixture, blending until completely smooth. Cover and refrigerate this creamy pudding.

Using a mixer, whip 1 cup of heavy cream with powdered sugar on high speed for 3-4 minutes until stiff peaks form. Chill the whipped cream until serving time.

In a skillet over medium heat, melt 2 tablespoons of butter. Stir in 1/2 cup of dark brown sugar, 1/4 cup of banana liqueur, and a pinch of ground cinnamon. Add sliced bananas and chopped walnuts, cooking for 4-5 minutes until bananas are heated through and caramelized.

To assemble your pudding, layer the cooled graham cracker crust, followed by the banana pudding, then a dollop of whipped cream, and top with the warm Bananas Foster mixture.